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Scientists Achieve Million-Fold Energy Enhancement in Diamond Optical Antennas

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Wednesday, June 12, 2024

Atomic antennas using diamonds enhance optical energy by a million-fold, enabling new physics research. This was achieved through global collaboration between theory and experiments. Credit: SciTechDaily.comTheory has become practice as new work from the University of Chicago Pritzker School of Molecular Engineering taps diamond defects’ remarkable ability to concentrate optical energy.Researchers have developed atomic antennas using germanium vacancy centers in diamonds, achieving a million-fold optical energy enhancement. This advancement allows the study of fundamental physics and opens new research avenues. The collaboration between theoretical and experimental teams was essential to this breakthrough.Atomic Antennas: Harnessing Light for Powerful SignalsSimilar to how a radio antenna captures a broadcast from the air and concentrates the energy into music, individual atoms can collect and concentrate the energy of light into a strong, localized signal that researchers can use to investigate the fundamental building blocks of matter. The more powerful the intensity enhancement, the better the antenna. However, scientists have never been able to tap the potentially huge intensity enhancements of some “atomic antennas” in solid materials simply because they were solids.Overcoming the Challenges of Solid Materials“Most of the time when you have atoms in solids, they interact with the environment. There’s a lot of disorder, they get shaken by phonons and face other disruptions that reduce the coherence of the signal,” said UChicago Pritzker School of Molecular Engineering Assistant Professor Alex High.In a new paper published on June 7 in Nature Photonics, a multi-institutional team led by the High Lab has cracked this problem. They have used germanium vacancy centers in diamonds to create an optical energy enhancement of six orders of magnitude, a regime challenging to reach with conventional antenna structures.PhD candidate Zixi Li at the UChicago Pritzker School of Molecular Engineering is the co-first author on a new paper from the lab of Asst. Prof. Alex High, which demonstrates a new way to provide more powerful measurements on the atomic level. Credit: Photo by Hong Qiao / UChicago Pritzker School of Molecular EngineeringGroundbreaking Optical Antennas With DiamondsThis million-fold energy enhancement creates what the paper calls an “exemplary” optical antenna and provides a new tool opening up entirely new research areas.“It’s not just a breakthrough in technology. It’s also a breakthrough in fundamental physics,” said PME PhD candidate Zixi Li, co-first author on the paper. “While it’s well-known that an excited atomic dipole can generate a near-filed with huge intensity, no one has ever demonstrated this in an experiment before.”From Theory to Practice: Realizing Optical AntennasThe core feature of an optical antenna is that it creates an oscillating electronic dipole when excited at resonance.“Optical antennas are basically structures that interact with electromagnetic fields and absorb or emit light at certain resonances, like the electrons moving between energy levels in these color centers,” High said.The electron oscillates when it transitions between an excited state and a ground state and concentrates a comparatively huge amount of energy, making an atomic optical dipole in a solid an excellent antenna – theoretically.“It’s not just a breakthrough in technology. It’s also a breakthrough in fundamental physics.”— UChicago Pritzker School of Molecular Engineering PhD candidate Zixi LiAddressing the Challenges in Solid-State AtomsWhat kept that ability theoretical was the fact the atoms were in solids, subject to all the jostling, electron interference and general noise that comes from being part of a tightly-packed structure. Color centers – small defects in diamonds and other materials with interesting quantum properties – provided the team a solution.“Something that’s been observed for the last seven or eight years is that certain types of color centers can be immune to these environmental effects,” High said.Potential of Quantum Mechanical Light EmissionThis opens intriguing research opportunities, said co-author Darrick Chang of the Institute of Photonic Sciences in Barcelona, Spain.“To me, the most interesting aspect of a color center is not just the field enhancement, but also the fact that the emitted light is intrinsically quantum mechanical,” he said. “That makes it intriguing to consider whether a ‘quantum optical antenna’ can have a different set of functionalities and working mechanisms as compared to a classical optical antenna.”Collaborations Paving the Way for InnovationsBut turning this theory into a practicable antenna took years, collaboration with researchers around the globe and theoretical guidance from UChicago’s Galli Group.“The collaboration between theory, computation and experiments initiated by Alex High not only contributed to understanding and interpreting the core science, but also opened new lines of research on the computational side,” said PME Liew Family Prof. Guilia Galli, a co-author on the paper. “The collaboration has been extremely fruitful.”‘The Magic of a Color Center’Imaging at the atomic level is a combination of amplification and bandwidth – the strength of the signal and the amount of signal you can study. Because of this, co-first author Xinghan Guo sees the new technique as complementary to, not replacing, existing techniques.“We offer a much higher amplification but our bandwidth is narrower,” said Guo, who recently completed his PhD at PME and is now a postdoctoral researcher at Yale. “If you have a very selective signal which has a narrow bandwidth but requires a lot of amplification, you can come to us.”Advantages of New TechniquesThe new technique offers other benefits than just a more powerful signal. While existing techniques like single-molecule Raman and FRET spectroscopy boost the signal by blasting it with light, this technique only requires nanowatts of energy to activate. This means a strong signal without the bleaching, heating and background fluorescence that excessive light creates.The germanium vacancy centers also do not dissipate energy as they are used, unlike conventional plasmonic antennas.“The magic of a color center is that it is simultaneously point-like and avoids the losses of a plasmonic material, allowing it to retain its extreme field enhancement,” Chang said.Future Discoveries With Optical AntennasFor High, the exciting part is not the new form of antenna, but the potential discoveries they will make.“What’s exciting is that this is a general feature,” High said. “We can integrate these color centers into a huge range of systems, and then we can use these as local antennas to grow new processes that both build new devices and help us understand how the universe works.”Reference: “Atomic optical antennas in solids” by Zixi Li, Xinghan Guo, Yu Jin, Francesco Andreoli, Anil Bilgin, David D. Awschalom, Nazar Delegan, F. Joseph Heremans, Darrick Chang, Giulia Galli and Alexander A. High, 7 June 2024, Nature Photonics.DOI: 10.1038/s41566-024-01456-5Funding: Q-NEXT, supported by the US Department of Energy, Office of Science, National Quantum Information Science Research Centers. Z.L. acknowledges support from the Kadanoff-Rice fellowship (grant no. NSF DMR-2011854). Diamond growth-related efforts were supported by the US Department of Energy, Office of Basic Energy Sciences, Materials Science and Engineering Division.

Theory has become practice as new work from the University of Chicago Pritzker School of Molecular Engineering taps diamond defects’ remarkable ability to concentrate optical...

Diamond Light Energy Physics Concept

Atomic antennas using diamonds enhance optical energy by a million-fold, enabling new physics research. This was achieved through global collaboration between theory and experiments. Credit: SciTechDaily.com

Theory has become practice as new work from the University of Chicago Pritzker School of Molecular Engineering taps diamond defects’ remarkable ability to concentrate optical energy.

Researchers have developed atomic antennas using germanium vacancy centers in diamonds, achieving a million-fold optical energy enhancement. This advancement allows the study of fundamental physics and opens new research avenues. The collaboration between theoretical and experimental teams was essential to this breakthrough.

Atomic Antennas: Harnessing Light for Powerful Signals

Similar to how a radio antenna captures a broadcast from the air and concentrates the energy into music, individual atoms can collect and concentrate the energy of light into a strong, localized signal that researchers can use to investigate the fundamental building blocks of matter.

The more powerful the intensity enhancement, the better the antenna. However, scientists have never been able to tap the potentially huge intensity enhancements of some “atomic antennas” in solid materials simply because they were solids.

Overcoming the Challenges of Solid Materials

“Most of the time when you have atoms in solids, they interact with the environment. There’s a lot of disorder, they get shaken by phonons and face other disruptions that reduce the coherence of the signal,” said UChicago Pritzker School of Molecular Engineering Assistant Professor Alex High.

In a new paper published on June 7 in Nature Photonics, a multi-institutional team led by the High Lab has cracked this problem. They have used germanium vacancy centers in diamonds to create an optical energy enhancement of six orders of magnitude, a regime challenging to reach with conventional antenna structures.

Zixi Li

PhD candidate Zixi Li at the UChicago Pritzker School of Molecular Engineering is the co-first author on a new paper from the lab of Asst. Prof. Alex High, which demonstrates a new way to provide more powerful measurements on the atomic level. Credit: Photo by Hong Qiao / UChicago Pritzker School of Molecular Engineering

Groundbreaking Optical Antennas With Diamonds

This million-fold energy enhancement creates what the paper calls an “exemplary” optical antenna and provides a new tool opening up entirely new research areas.

“It’s not just a breakthrough in technology. It’s also a breakthrough in fundamental physics,” said PME PhD candidate Zixi Li, co-first author on the paper. “While it’s well-known that an excited atomic dipole can generate a near-filed with huge intensity, no one has ever demonstrated this in an experiment before.”

From Theory to Practice: Realizing Optical Antennas

The core feature of an optical antenna is that it creates an oscillating electronic dipole when excited at resonance.

“Optical antennas are basically structures that interact with electromagnetic fields and absorb or emit light at certain resonances, like the electrons moving between energy levels in these color centers,” High said.

The electron oscillates when it transitions between an excited state and a ground state and concentrates a comparatively huge amount of energy, making an atomic optical dipole in a solid an excellent antenna – theoretically.

“It’s not just a breakthrough in technology. It’s also a breakthrough in fundamental physics.”

UChicago Pritzker School of Molecular Engineering PhD candidate Zixi Li

Addressing the Challenges in Solid-State Atoms

What kept that ability theoretical was the fact the atoms were in solids, subject to all the jostling, electron interference and general noise that comes from being part of a tightly-packed structure. Color centers – small defects in diamonds and other materials with interesting quantum properties – provided the team a solution.

“Something that’s been observed for the last seven or eight years is that certain types of color centers can be immune to these environmental effects,” High said.

Potential of Quantum Mechanical Light Emission

This opens intriguing research opportunities, said co-author Darrick Chang of the Institute of Photonic Sciences in Barcelona, Spain.

“To me, the most interesting aspect of a color center is not just the field enhancement, but also the fact that the emitted light is intrinsically quantum mechanical,” he said. “That makes it intriguing to consider whether a ‘quantum optical antenna’ can have a different set of functionalities and working mechanisms as compared to a classical optical antenna.”

Collaborations Paving the Way for Innovations

But turning this theory into a practicable antenna took years, collaboration with researchers around the globe and theoretical guidance from UChicago’s Galli Group.

“The collaboration between theory, computation and experiments initiated by Alex High not only contributed to understanding and interpreting the core science, but also opened new lines of research on the computational side,” said PME Liew Family Prof. Guilia Galli, a co-author on the paper. “The collaboration has been extremely fruitful.”

‘The Magic of a Color Center’

Imaging at the atomic level is a combination of amplification and bandwidth – the strength of the signal and the amount of signal you can study. Because of this, co-first author Xinghan Guo sees the new technique as complementary to, not replacing, existing techniques.

“We offer a much higher amplification but our bandwidth is narrower,” said Guo, who recently completed his PhD at PME and is now a postdoctoral researcher at Yale. “If you have a very selective signal which has a narrow bandwidth but requires a lot of amplification, you can come to us.”

Advantages of New Techniques

The new technique offers other benefits than just a more powerful signal. While existing techniques like single-molecule Raman and FRET spectroscopy boost the signal by blasting it with light, this technique only requires nanowatts of energy to activate. This means a strong signal without the bleaching, heating and background fluorescence that excessive light creates.

The germanium vacancy centers also do not dissipate energy as they are used, unlike conventional plasmonic antennas.

“The magic of a color center is that it is simultaneously point-like and avoids the losses of a plasmonic material, allowing it to retain its extreme field enhancement,” Chang said.

Future Discoveries With Optical Antennas

For High, the exciting part is not the new form of antenna, but the potential discoveries they will make.

“What’s exciting is that this is a general feature,” High said. “We can integrate these color centers into a huge range of systems, and then we can use these as local antennas to grow new processes that both build new devices and help us understand how the universe works.”

Reference: “Atomic optical antennas in solids” by Zixi Li, Xinghan Guo, Yu Jin, Francesco Andreoli, Anil Bilgin, David D. Awschalom, Nazar Delegan, F. Joseph Heremans, Darrick Chang, Giulia Galli and Alexander A. High, 7 June 2024, Nature Photonics.
DOI: 10.1038/s41566-024-01456-5

Funding: Q-NEXT, supported by the US Department of Energy, Office of Science, National Quantum Information Science Research Centers. Z.L. acknowledges support from the Kadanoff-Rice fellowship (grant no. NSF DMR-2011854). Diamond growth-related efforts were supported by the US Department of Energy, Office of Basic Energy Sciences, Materials Science and Engineering Division.

Read the full story here.
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BPA faces suit over energy market decision that opponents say would raise rates

The lawsuit comes after governors, lawmakers, utility regulators and renewable energy proponents in the region unsuccessfully pressed the BPA to reconsider its plans.

Five energy and conservation nonprofits are suing the Bonneville Power Administration over its decision to join a new energy trading market, claiming it will raise electricity and transmission costs in Oregon and across the region. The lawsuit, filed Thursday in the 9th U.S. Circuit Court of Appeals, alleges that BPA’s move violates the Northwest Power Act and the National Environmental Policy Act and will also weaken energy grid reliability and reduce access to clean energy. BPA, the Northwest’s largest transmission grid operator, in May announced it would join the Arkansas-based Southwest Power Pool day-ahead market known as “Markets Plus” instead of joining California’s day-ahead market. The Southwest market is smaller with fewer electrical generation resources, experts say. Prior to that decision, Pacific Northwest governors, lawmakers, utility regulators and renewable energy proponents had pressed the BPA for months to reconsider its plans, which the agency initially announced in March.The nonprofits involved in the legal challenge are the Oregon Citizens’ Utility Board, a watchdog organization that advocates for utility customers; national environmental group the Sierra Club; the Montana Environmental Information Center, which promotes clean energy; the Idaho Conservation League, a natural landscape conservation group; and the NW Energy Coalition, which promotes affordable energy policies. The groups, represented by San Francisco-based environmental law nonprofit Earthjustice, want the court to vacate BPA’s decision, require the agency to prepare an environmental impact statement and rescind the financial commitments already made to the Southwest energy market.The BPA’s spokesperson Nick Quinata declined to comment on the pending litigation. Previously, the agency said the Southwest day-ahead market is superior to the California one because it would allow BPA to remain more independent due to its market design and governance structure. BPA, part of the U.S. Department of Energy, markets hydropower from 31 federal dams in the Columbia River Basin and supplies a third of the Northwest’s electricity, most of it to publicly owned rural utilities and electric cooperatives. It also owns and operates 15,000 miles – 75% – of the Northwest’s high-voltage transmission lines. Nearly every electric utility in Oregon benefits from either the clean hydroelectricity or the transmission lines controlled by BPA. BPA’s decision sets the stage for having two energy markets across the West.The lawsuit says that will likely lead to rising prices and blackouts during periods of high electricity demand because of the complexity of transmitting power across boundaries between different utilities and the agreements required for such transfers. Oregon’s two largest utilities, investor-owned Portland General Electric and Pacific Power, have both signed agreements to join California’s day-ahead market instead. They, too, have argued that once BPA leaves the Western market, the available energy they can purchase would diminish and become more expensive, leading to higher prices for customers across the region.Regional electricity providers also may have to construct additional power generation facilities, increase operation of existing facilities or both, to make up for BPA’s participation in a smaller and less efficient energy market, the suit contends. It could also increase reliance on generation resources powered by fossil fuels such as coal or natural gas plants because clean energy isn’t as widely available in the smaller Southwest market, the suit says. The Northwest Power Act, passed by Congress in the 1980s, requires BPA to provide low-cost power to the region while encouraging renewable energy, conservation and protection of fish and wildlife.BPA violated those duties when it chose the Southwest market option, according to the lawsuit. The groups also allege BPA’s market choice could harm fish and wildlife in the Columbia basin because it could alter the operation of the federal hydroelectric dams from which Bonneville markets power. The lawsuit claims BPA failed to comply with federal environmental law by not conducting any environmental impact analysis on impacts to fish and wildlife before making its decision. The Citizens’ Utility Board, a party to the lawsuit, said it hoped the BPA reverses course – otherwise its decision will splinter the West’s electricity markets, costing utility customers billions of dollars at a time when many are already dealing with skyrocketing bills.The board, as well as other critics of BPA’s decision, have pointed to an initiative developing an independent governance structure for California’s day-ahead market.“Oregon is facing overlapping energy challenges: rising utility bills, rising electricity demand from data centers, and stalling progress on meeting clean energy requirements. The last thing we need is for one of our region’s largest clean energy suppliers to reduce ties with the Pacific Northwest,” said the group’s spokesperson Charlotte Shuff. — Gosia Wozniacka covers environmental justice, climate change, the clean energy transition and other environmental issues. Reach her at gwozniacka@oregonian.com or 971-421-3154.If you purchase a product or register for an account through a link on our site, we may receive compensation. By using this site, you consent to our User Agreement and agree that your clicks, interactions, and personal information may be collected, recorded, and/or stored by us and social media and other third-party partners in accordance with our Privacy Policy.

States, enviro groups fight Trump plan to keep dirty power plants going

In late spring, the Department of Energy ordered two aging and costly fossil-fueled power plants that were on the verge of shutting down to stay open. The agency claimed that the moves were necessary to prevent the power grid from collapsing — and that it has the power to force the plants to stay open even if the…

In late spring, the Department of Energy ordered two aging and costly fossil-fueled power plants that were on the verge of shutting down to stay open. The agency claimed that the moves were necessary to prevent the power grid from collapsing — and that it has the power to force the plants to stay open even if the utilities, state regulators, and grid operators managing them say that no such emergency exists. But state regulators, regional grid operators, environmental groups, and consumer groups are pushing back on the notion that the grids in question even need these interventions — and are challenging the legality of the DOE’s stay-open orders. The DOE claimed that the threat of large-scale grid blackouts forced its hand. But state utility regulators, environmental groups, consumer advocates, and energy experts say that careful analysis from the plant’s owners, state regulators, regional grid operators, and grid reliability experts had determined both plants could be safely closed. These groups argue that clean energy, not fossil fuels, are the true solution to the country’s grid challenges — even if the ​“big, beautiful” bill signed by Trump last week will make those resources more expensive to build. Some of the environmental organizations challenging DOE’s orders have pledged to take their case to federal court if necessary. “We need to get more electrons on the grid. We need those to be clean, reliable, and affordable,” said Robert Routh, Pennsylvania climate and energy policy director for the Natural Resources Defense Council, one of the groups demanding that DOE reconsider its orders. Keeping J.H. Campbell and Eddystone open ​“results in the exact opposite. It’s costly, harmful, unnecessary, and unlawful.” Taking on the DOE’s grid emergency claims The groups challenging the DOE’s J.H. Campbell and Eddystone stay-open orders point out that the agency is using a power originally designed to protect the grid against unanticipated emergencies, including during wartime, but without proving that such an emergency is underway. “This authority that the Department of Energy is acting under — Section 202(c) of the Federal Power Act — is a very tailored emergency authority,” said Caroline Reiser, NRDC senior attorney for climate and energy. ​“Congress intentionally wrote it only to be usable in specific, narrow, short-term emergencies. This is not that.” For decades, the DOE has used its Section 202(c) power sparingly, and only in response to requests from utilities or grid operators to waive federal air pollution regulations or other requirements in moments when the grid faces imminent threats like widespread power outages, Reiser said. But DOE’s orders for Eddystone and J.H. Campbell were not spurred by requests from state regulators or regional grid operators. In fact, the orders caught those parties by surprise. They also came mere days before the plants were set to close down and after years of effort to ensure their closure wouldn’t threaten grid reliability. J.H. Campbell was scheduled to close in May under a plan that has been in the works since 2021 as part of a broader agreement between utility Consumers Energy and state regulators, and which was approved by the Midcontinent Independent System Operator (MISO), the entity that manages grid reliability across Michigan and 14 other states. “The plant is really old, unreliable, extremely polluting, and extremely expensive,” Reiser said. ​“Nobody is saying that this plant is needed or is going to be beneficial for any reliability purposes.” To justify its stay-open order, DOE cited reports from the North American Electric Reliability Corp. (NERC), a nonprofit regulatory authority that includes utilities and grid operators in the U.S. and Canada. NERC found MISO is at higher risk of summertime reliability problems than other U.S. grid regions, but environmental groups argue in their rehearing request that DOE has ​“misrepresented the reports on which it relies,” and that Consumers Energy, Michigan regulators, and MISO have collectively shown closing the plant won’t endanger grid reliability. Eddystone, which had operated only infrequently over the past few years, also went through a rigorous process with mid-Atlantic grid operator PJM Interconnection to ensure its closure wouldn’t harm grid reliability. The DOE’s reason for keeping that plant open is based on a report from PJM that states the grid operator might need to ask utility customers to use less power if it faces extreme conditions this summer — an even scantier justification than what the agency cited in its J.H. Campbell order, Reiser said. As long as the DOE continues to take the position that it can issue emergency stay-open orders to any power plant it decides to, these established methods for managing plant closures and fairly allocating costs will be thrown into disarray, she said. “We have a system of competitive energy markets in the United States that is successful in keeping the lights on and maintaining reliability the vast, vast majority of the time,” Reiser said. ​“The Department of Energy stepping in and using a command-and-control system interferes with those markets.”

Designing a new way to optimize complex coordinated systems

Using diagrams to represent interactions in multipart systems can provide a faster way to design software improvements.

Coordinating complicated interactive systems, whether it’s the different modes of transportation in a city or the various components that must work together to make an effective and efficient robot, is an increasingly important subject for software designers to tackle. Now, researchers at MIT have developed an entirely new way of approaching these complex problems, using simple diagrams as a tool to reveal better approaches to software optimization in deep-learning models.They say the new method makes addressing these complex tasks so simple that it can be reduced to a drawing that would fit on the back of a napkin.The new approach is described in the journal Transactions of Machine Learning Research, in a paper by incoming doctoral student Vincent Abbott and Professor Gioele Zardini of MIT’s Laboratory for Information and Decision Systems (LIDS).“We designed a new language to talk about these new systems,” Zardini says. This new diagram-based “language” is heavily based on something called category theory, he explains.It all has to do with designing the underlying architecture of computer algorithms — the programs that will actually end up sensing and controlling the various different parts of the system that’s being optimized. “The components are different pieces of an algorithm, and they have to talk to each other, exchange information, but also account for energy usage, memory consumption, and so on.” Such optimizations are notoriously difficult because each change in one part of the system can in turn cause changes in other parts, which can further affect other parts, and so on.The researchers decided to focus on the particular class of deep-learning algorithms, which are currently a hot topic of research. Deep learning is the basis of the large artificial intelligence models, including large language models such as ChatGPT and image-generation models such as Midjourney. These models manipulate data by a “deep” series of matrix multiplications interspersed with other operations. The numbers within matrices are parameters, and are updated during long training runs, allowing for complex patterns to be found. Models consist of billions of parameters, making computation expensive, and hence improved resource usage and optimization invaluable.Diagrams can represent details of the parallelized operations that deep-learning models consist of, revealing the relationships between algorithms and the parallelized graphics processing unit (GPU) hardware they run on, supplied by companies such as NVIDIA. “I’m very excited about this,” says Zardini, because “we seem to have found a language that very nicely describes deep learning algorithms, explicitly representing all the important things, which is the operators you use,” for example the energy consumption, the memory allocation, and any other parameter that you’re trying to optimize for.Much of the progress within deep learning has stemmed from resource efficiency optimizations. The latest DeepSeek model showed that a small team can compete with top models from OpenAI and other major labs by focusing on resource efficiency and the relationship between software and hardware. Typically, in deriving these optimizations, he says, “people need a lot of trial and error to discover new architectures.” For example, a widely used optimization program called FlashAttention took more than four years to develop, he says. But with the new framework they developed, “we can really approach this problem in a more formal way.” And all of this is represented visually in a precisely defined graphical language.But the methods that have been used to find these improvements “are very limited,” he says. “I think this shows that there’s a major gap, in that we don’t have a formal systematic method of relating an algorithm to either its optimal execution, or even really understanding how many resources it will take to run.” But now, with the new diagram-based method they devised, such a system exists.Category theory, which underlies this approach, is a way of mathematically describing the different components of a system and how they interact in a generalized, abstract manner. Different perspectives can be related. For example, mathematical formulas can be related to algorithms that implement them and use resources, or descriptions of systems can be related to robust “monoidal string diagrams.” These visualizations allow you to directly play around and experiment with how the different parts connect and interact. What they developed, he says, amounts to “string diagrams on steroids,” which incorporates many more graphical conventions and many more properties.“Category theory can be thought of as the mathematics of abstraction and composition,” Abbott says. “Any compositional system can be described using category theory, and the relationship between compositional systems can then also be studied.” Algebraic rules that are typically associated with functions can also be represented as diagrams, he says. “Then, a lot of the visual tricks we can do with diagrams, we can relate to algebraic tricks and functions. So, it creates this correspondence between these different systems.”As a result, he says, “this solves a very important problem, which is that we have these deep-learning algorithms, but they’re not clearly understood as mathematical models.” But by representing them as diagrams, it becomes possible to approach them formally and systematically, he says.One thing this enables is a clear visual understanding of the way parallel real-world processes can be represented by parallel processing in multicore computer GPUs. “In this way,” Abbott says, “diagrams can both represent a function, and then reveal how to optimally execute it on a GPU.”The “attention” algorithm is used by deep-learning algorithms that require general, contextual information, and is a key phase of the serialized blocks that constitute large language models such as ChatGPT. FlashAttention is an optimization that took years to develop, but resulted in a sixfold improvement in the speed of attention algorithms.Applying their method to the well-established FlashAttention algorithm, Zardini says that “here we are able to derive it, literally, on a napkin.” He then adds, “OK, maybe it’s a large napkin.” But to drive home the point about how much their new approach can simplify dealing with these complex algorithms, they titled their formal research paper on the work “FlashAttention on a Napkin.”This method, Abbott says, “allows for optimization to be really quickly derived, in contrast to prevailing methods.” While they initially applied this approach to the already existing FlashAttention algorithm, thus verifying its effectiveness, “we hope to now use this language to automate the detection of improvements,” says Zardini, who in addition to being a principal investigator in LIDS, is the Rudge and Nancy Allen Assistant Professor of Civil and Environmental Engineering, and an affiliate faculty with the Institute for Data, Systems, and Society.The plan is that ultimately, he says, they will develop the software to the point that “the researcher uploads their code, and with the new algorithm you automatically detect what can be improved, what can be optimized, and you return an optimized version of the algorithm to the user.”In addition to automating algorithm optimization, Zardini notes that a robust analysis of how deep-learning algorithms relate to hardware resource usage allows for systematic co-design of hardware and software. This line of work integrates with Zardini’s focus on categorical co-design, which uses the tools of category theory to simultaneously optimize various components of engineered systems.Abbott says that “this whole field of optimized deep learning models, I believe, is quite critically unaddressed, and that’s why these diagrams are so exciting. They open the doors to a systematic approach to this problem.”“I’m very impressed by the quality of this research. ... The new approach to diagramming deep-learning algorithms used by this paper could be a very significant step,” says Jeremy Howard, founder and CEO of Answers.ai, who was not associated with this work. “This paper is the first time I’ve seen such a notation used to deeply analyze the performance of a deep-learning algorithm on real-world hardware. ... The next step will be to see whether real-world performance gains can be achieved.”“This is a beautifully executed piece of theoretical research, which also aims for high accessibility to uninitiated readers — a trait rarely seen in papers of this kind,” says Petar Velickovic, a senior research scientist at Google DeepMind and a lecturer at Cambridge University, who was not associated with this work. These researchers, he says, “are clearly excellent communicators, and I cannot wait to see what they come up with next!”The new diagram-based language, having been posted online, has already attracted great attention and interest from software developers. A reviewer from Abbott’s prior paper introducing the diagrams noted that “The proposed neural circuit diagrams look great from an artistic standpoint (as far as I am able to judge this).” “It’s technical research, but it’s also flashy!” Zardini says.

The UK Says at an Energy Summit That Green Power Will Boost Security, as the US Differs

Britain has announced a major investment in wind power as it hosts an international summit on energy security

LONDON (AP) — Britain announced a major investment in wind power Thursday as it hosted an international summit on energy security — with Europe and the United States at odds over whether to cut their reliance on fossil fuels.U.K. Prime Minister Keir Starmer said the government will invest 300 million pounds ($400 million) in boosting Britain’s capacity to manufacture components for the offshore wind industry, a move it hopes will encourage private investment in the U.K.’s renewable energy sector.“As long as energy can be weaponized against us, our countries and our citizens are vulnerable and exposed,” U.K. Energy Secretary Ed Miliband told delegates.He said “low-carbon power” was a route to energy security as well as a way to slow climate change.Britain now gets more than half its electricity from renewable sources such as wind and solar power, and the rest from natural gas and nuclear energy. It aims to generate all the U.K.’s energy from renewable sources by 2030.Tommy Joyce, U.S. acting assistant secretary of energy for international affairs, told participants they should be “honest about the world’s growing energy needs, not focused on net-zero politics.”He called policies that push for clean power over fossil fuels "harmful and dangerous," and claimed building wind turbines requires "concessions to or coercion from China" because it supplies necessary rare minerals.Hosted by the British government and the International Energy Agency, the two-day summit brings together government ministers from 60 countries, senior European Union officials, energy sector CEOs, heads of international organizations and nonprofits to assess risks to the global energy system and figure out solutions. Associated Press writer Jennifer McDermott contributed to this story. ___The Associated Press’ climate and environmental coverage receives financial support from multiple private foundations. AP is solely responsible for all content. Find AP’s standards for working with philanthropies, a list of supporters and funded coverage areas at AP.org.Copyright 2025 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.Photos You Should See - Feb. 2025

Steelhead trout rescued from Palisades fire spawn in their new Santa Barbara County home

After a stressful journey out of the burn zone in Malibu, the endangered trout have spawned in their adopted stream in Santa Barbara County.

Wildlife officials feared critically endangered steelhead trout rescued from the Palisades fire burn scar might not be up for spawning after all they’d been through over the last few months.After their watershed in the Santa Monica Mountains was scorched in January, the fish were stunned with electricity, scooped up in buckets, trucked to a hatchery, fed unfamiliar food and then moved to a different creek. It was all part of a liberation effort pulled off in the nick of time. “This whole thing is just a very stressful and traumatic event, and I’m happy that we didn’t really kill many fish,” said Kyle Evans, an environmental program manager for the California Department of Fish and Wildlife, which led the rescue. “But I was concerned that I might have just disrupted this whole months-long process of getting ready to spawn.” Steelhead were once abundant in Southern California, but their numbers plummeted amid coastal development and overfishing. A distinct Southern California population is listed as endangered at the state and federal level. (Alex Vejar / California Department of Fish and Wildlife) But this month spawn they did.It’s believed that there are now more than 100 baby trout swishing around their new digs in Arroyo Hondo Creek in Santa Barbara County.Their presence is a triumph — for the species and for their adopted home.However, more fish require more suitable habitat, which is lacking in Southern California — in part due to drought and the increased frequency of devastating wildfires. Steelhead trout are the same species as rainbow trout, but they have different lifestyles. Steelheads migrate to the ocean and return to their natal streams to spawn, while rainbows spend their lives in freshwater.Steelhead were once abundant in Southern California, but their numbers plummeted amid coastal development and overfishing. A distinct Southern California population is listed as endangered at the state and federal level.The young fish sighted this month mark the next generation of what was the last population of steelhead in the Santa Monica Mountains, a range that stretches from the Hollywood Hills to Point Mugu in Ventura County. They also represent the return of a species to a watershed that itself was devastated by a fire four years ago, but has since recovered. It’s believed that there are now more than 100 baby trout swishing around their new digs in Arroyo Hondo Creek in Santa Barbara County. (Kyle Kusa / Land Trust for Santa Barbara County) The Alisal blaze torched roughly 95% of the Arroyo Hondo Preserve located west of Santa Barbara, and subsequent debris flows choked the creek of the same name that housed steelhead. All the fish perished, according to Meredith Hendricks, executive director of the Land Trust for Santa Barbara County, a nonprofit organization that owns and manages the preserve.“To be able to … offer space for these fish to be transplanted to — when we ourselves had experienced a similar situation but lost our fish — it was just a really big deal,” Hendricks said. Arroyo Hondo Creek bears similarities to the trout’s native Topanga Creek; they are both coastal streams of roughly the same size. And it has a bonus feature: a state-funded fish passage constructed under Highway 101 in 2008, which improved fish movement between the stream and the ocean.Spawning is a biologically and energetically demanding endeavor for steelhead, and the process likely began in December or earlier, according to Evans.That means it was already underway when 271 steelhead were evacuated in January from Topanga Creek, a biodiversity hot spot located in Malibu that was badly damaged by the Palisades fire.It continued when they were hauled about 50 miles north to a hatchery in Fillmore, where they hung out until 266 of them made it to Arroyo Hondo the following month.State wildlife personnel regularly surveyed the fish in their new digs but didn’t see the spawning nests, which can be missed. VIDEO | 00:16 Steelhead trout in Arroyo Hondo Creek in Santa Barbara County Steelhead trout in Arroyo Hondo Creek in Santa Barbara County. (Calif. Dept. of Fish & Game) Then, on April 7, Evans got a text message from the Land Trust’s land programs director, Leslie Chan, with a video that appeared to show a freshly hatched young-of-the-year — the wonky name for fish born during the steelheads’ sole annual spawn.The following day, Evans’ team was dispatched to the creek and confirmed the discovery. They tallied about 100 of the newly hatched fish. The young trout span roughly one inch and, as Evans put it, aren’t too bright. They hang out in the shallows and don’t bolt from predators.“They’re kind of just happy to be alive, and they’re not really trying to hide,” he said.By the end of summer, Evans estimates two-thirds will die off. But the survivors are enough to keep the population charging onward. Evans hopes that in a few years, there will be three to four times the number of fish that initially moved in.The plan is to eventually relocate at least some back to their native home of Topanga Creek.Right now, Topanga “looks pretty bad,” Evans said. The Palisades fire stripped the surrounding hillsides of vegetation, paving the way for dirt, ash and other material to pour into the waterway. Another endangered fish, northern tidewater gobies, were rescued from the same watershed shortly before the steelhead were liberated. Within two days of the trouts’ removal, the first storm of the season arrived, likely burying the remaining fish in a muddy slurry. Citizen scientists Bernard Yin, center, and Rebecca Ramirez, right, join government agency staffers in rescuing federally endangered fish in the Topanga Lagoon in Malibu on Jan. 17. (Christina House / Los Angeles Times) Evans expects it will be about four years before Topanga Creek is ready to support steelhead again, based on his experience observing streams recover after the Thomas, Woolsey, Alisal and other fires. There’s also discussion about moving around steelhead to create backup populations should calamity befall one, as well as boost genetic diversity of the rare fish.For example, some of the steelhead saved from Topanga could be moved to Malibu Creek, another stream in the Santa Monica Mountains that empties into Santa Monica Bay. There are efforts underway to remove the 100-foot Rindge Dam in Malibu Creek to open up more habitat for the fish.“As we saw, if you have one population in the Santa Monica Mountains and a fire happens, you could just lose it forever,” Evans said. “So having fish in multiple areas is the kind of way to defend against that.”With the Topanga Creek steelhead biding their time up north, it’s believed there are none currently inhabiting the Santa Monicas. Habitat restoration is key for the species’ survival, according to Evans, who advocates for directing funding to such efforts, including soon-to-come-online money from Proposition 4, a $10-billion bond measure to finance water, clean energy and other environmental projects.“It doesn’t matter how many fish you have, or if you’re growing them in a hatchery, or what you’re doing,” he said. “If they can’t be supported on the landscape, then there’s no point.”Some trout will end up making their temporary lodging permanent, according to Hendricks, of the Land Trust. Arroyo Hondo is a long creek with plenty of nooks and crannies for trout to hide in. So when it comes time to bring the steelhead home, she said, “I’m sure some will get left behind.”

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