Nicole Yunger Halpern Ponders Quantum Mechanics, Thermodynamics, and Everything Else

There is a well-known saying, of disputed origin(link is external), that dissuades students and even working physicists from thinking too deeply about the meaning behind quantum physics. “Shut up and calculate,” it goes. Nicole Yunger Halpern, an affiliate of JQI and the newest Fellow of the Joint Center for Quantum Information and Computer Science (QuICS), was never one to abide by this mantra.

Instead, Yunger Halpern, who is also a physicist at the National Institute of Standards and Technology, brings a vast intellectual curiosity to physics, from tackling abstract theory to collaborating with experimentalists, all the while drawing distinct connections between diverse disciplines of physics. She also brings her research to life through writing, imbuing it with historical, philosophical, and even artistic context.Photo by John T. Consoli/University of MarylandPhoto by John T. Consoli/University of Maryland

Her self-titled research direction—at the intersection of quantum information theory and thermodynamics—is “quantum steampunk,” after the steampunk genre of literature, art and film that envisions a 19th century world where steam engines power futuristic gadgets, like flying boats and robots. Her book(link is external) of the same title is scheduled for publication in the spring of 2022. She will discuss it at the physics colloquium on Tues., March 29 at 4 p.m. in room 1412 of the John S. Toll Physics Building. 

Thermodynamics, developed largely in the 19th century, is the “steam” in Yunger Halpern’s research, merging with the futuristic science non-fiction that is quantum mechanics. Quantum thermodynamics explores how quantum mechanics can impact and enhance thermodynamic problems, such as channeling energy and heat to perform work, and it raises new questions about information transfer in the process. “What steampunk fans dream,” Yunger Halpern writes in her Ph.D. thesis(link is external), “quantum-information thermodynamicists live.”

On top of helping bridge the 19th and 21st centuries, Yunger Halpern brings the tools of quantum information thermodynamics to other disciplines. Her work on quantum scrambling(link is external) is relevant to black hole physics; her thermodynamic theories(link is external) straddle physics and chemistry; experimental realizations of her proposals have brought collaborations with condensed matter(link is external) and atomic, molecular and optical physicists(link is external); her studies of quantum mechanics have touched on information theory(link is external); her work on thermodynamics ventures into machine learning(link is external); and she’s even proposed an idea for quantum voting(link is external).

Yunger Halpern’s voracious appetite for ideas from diverse disciplines dates to her childhood in Florida. “I grew up reading basically all the time,” she recalls. “I would read while waiting for my parents to pick me up from school; while standing in line; and while in restaurants, waiting for food to arrive. I was interested in everything.”

As early as high school, thermodynamics caught Yunger Halpern’s eye. She remembers learning about entropy, a measure of disorder in a collection of particles, in a biology class. The second law of thermodynamics states that entropy, once it increases, can never go back down—a familiar concept to anyone who’s ever tried to stuff toothpaste back into the tube or unscramble an egg.

Some physicists believe that this irreversibility is what gives time its forward direction. “I’m fascinated by entropy,” Yunger Halpern says, “because it’s this abstract concept, quantified with a funny-looking function, but it has such important real-life implications.”

Yet, despite the early fascination with entropy and a high school physics class she loved, Yunger Halpern was still not willing to put on academic blinders after enrolling at Dartmouth College. “Two physics professors helped me design a major that enabled me to view physics from many perspectives,” she explains. “It was partway between the standard physics major and the create-your-own major.” The bespoke major included conventional physics courses combined with some math, philosophy and history.

It was a history of science class in her final term at Dartmouth that further pushed Yunger Halpern to make physics her primary focus, and to pursue graduate school. She was the only student in the class with a scientific background, and she noticed this gave her a different perspective on the course. “I couldn’t help noticing that I understood these topics more deeply than my classmates,” she says, “and I realized that I wouldn’t have been satisfied if I’d learned the material strictly at the level required for the history course.”

Similarly, she realized, she wouldn’t be satisfied if she refrained from studying a host of other topics—cosmology, field theory, etc.—at the level required of a physics student. “So, I was determined to remain a physics student—to study physics more deeply,” she says.

After completing her degree at Dartmouth, Yunger Halpern continued to follow a somewhat unconventional path. She spent a year as a research assistant at Lancaster University in England, followed by a one-year master’s program at the Perimeter Institute for Theoretical Physics in Waterloo, Canada. After starting a Ph.D. program at Caltech, she spent another semester as a visiting graduate student in Oxford, England.

It was during her master’s studies that Yunger Halpern had her first taste of combining quantum information theory with thermodynamics, under the guidance of then-postdoc Markus P. Müller and faculty member Robert Spekkens. They made use of quantum resource theories—a set of mathematical tools that look at quantum objects as resources that can be spent to accomplish a task—as a framework for thermodynamics(link is external).

Yunger Halpern reveled in the interdisciplinary nature of the work, as well as its real-world relevance. “That project was exactly the springboard that I’d sought to embark on research in quantum information theory and thermodynamics,” she says.

This set the course for her quantum steampunk career.

Propelled forward by her deepening passion, Yunger Halpern attended graduate school at Caltech under the mentorship of John Preskill, a giant in the field of quantum information science. “At the time, I was interested in a very theoretical, abstract flavor of quantum thermodynamics,” she explains. “Very few researchers in the United States supported it. But I told John what I wanted to do, and he said, ‘Ok. Do it.’ I felt that I’d have the freedom and support to undertake the research that I felt drawn to.”

This freedom brought her to a key insight(link is external) at the intersection of two seemingly disparate questions—how much work you have to do to push a collection of particles into a different configuration (like squeezing toothpaste into a travel-sized tube) and what happens when information is thrown into a black hole. Simply put, both processes depend crucially on the direction of time, like the toothpaste that won’t go back in the tube. Noticing this connection allowed Yunger Halpern to derive an equation relating quantum scrambling—the thing black holes are thought to do with information—to something that could be measured in the lab. Experiments realizing a simpler version of Yunger Halpern’s protocol were carried out(link is external), not inside a black hole, but in the lab of Kater Murch at Washington University in St. Louis.

Next, Yunger Halpern and her collaborators designed a truly steampunk invention(link is external): an analog of a steam engine that relies on an exotic quantum phase. This phase’s superpower is that it thermalizes very slowly or not at all, akin to an ice cube that stays cold on a warm summer day. It’s a collection of quantum particles that are kept in a box with a jagged and disorderly floor, creating a randomness that prevents the particles from freely bumping into each other and exchanging energy in a phenomenon known as many-body localization (MBL).

Drawing on ideas from her research at Perimeter, Yunger Halpern, with her collaborators, realized that a state that does not thermalize could be used as a resource. The engine, which they called ‘MBL-mobile’, is a four-stroke cycle that takes a collection of quantum particles in and out of the MBL phase to extract work.

At the beginning of her graduate career, alongside her research, Yunger Halpern committed to writing a blog post every month for Caltech’s blog Quantum Frontiers(link is external). This is a habit she’s kept to this day, having recently published her 100th post(link is external).

Through the blog, she’s managed to continue cultivating her lifelong love of writing. “I was writing stories as early as second grade,” she says. “The best physicists I’ve met explain their science in terms of stories colored by a few simple, basic equations, so writing stories about my physics regularly feels natural.”

Yunger Halpern’s blog posts touch on literature, history and anthropology from all over the world, drawing analogies and placing her work as a scientist into a larger context. “It provides a useful creative outlet,” she says. “Physicists value creativity, but there are some things that even we aren’t allowed to write in papers. I can write those things on the blog, which keeps my imagination in high gear and so enhances my physics.”

After Yunger Halpern moved on to a postdoctoral position at Harvard University, her writing landed her a feature story in Scientific American(link is external). Now, her new book, “Quantum Steampunk: The Physics of Yesterday’s Tomorrow,”(link is external) is about to hit bookstores nationwide. “The book is almost entirely nonfiction,” she says, “but each chapter begins with a snippet from an imaginary quantum-steampunk novel. I also worked with my editors and illustrator to bring out the steampunk aesthetic of quantum thermodynamics—not only in the explanations, but also in the figures and even in the fonts.”

Photo by John T. Consoli/University of MarylandPhoto by John T. Consoli/University of MarylandAt the University of Maryland, Yunger Halpern looks forward to forging new collaborations with senior researchers as well as training young scientists. “The people at Maryland—the colossal quantum and statistical-mechanics communities—certainly drew me. I have worked with Chris Jarzynski, who’s a wonderful scientist and a wonderful person, and I’ve visited the College Park campus several times over the years because I simply couldn't stay away from the research.”

She is also drawn to Maryland’s interdisciplinary structure, believing it will feed her insatiable drive to connect scientific disciplines. “I’m looking forward to making even more new connections,” she says.

Original story by Dina Genkina: https://jqi.umd.edu/news/nicole-yunger-halpern-ponders-quantum-mechanics-thermodynamics-and-everything-else

Faculty, Staff, Student and Alumni Awards & Notes

We proudly recognize members of our community who recently garnered major honors, began new positions and more.

Faculty and Staff 
  • Ruba Abukhdeir joined the department as the Director of Business and Finance. 
  • Kaustubh Agashe, Mohammad Hafezi and Arpita Upadhyaya were elected Fellows of the American Physical Society.
  • Jesse Anderson retired on December 31 after 34 years with the department. 
  • Lea Bartolome received the department's Staff Excellence Award. 
  • Alessandra Buonanno received the Balzan Prize.
  • Sankar Das Sarma was named a highly cited researcher by Clarivate Analytics. He also wrote a commentary for Physics Today. He recently discussed the latest developments in topological phases in quantum computing at a Microsoft conference. 
  • Work by Jim Drake on the heliosphere was described in Phys.org.
  • James Ellsworth joined the department as assistant director for of procurement, inventory and receiving.
  • Sarah Eno was elected a Fellow of the American Association for the Advancement of Science. 
  • Manuel Franco Sevilla was named liaison between EF and Rare Processes and Precision Measurement group at Snowmass.
  • Victor Galitski was quoated in Physics magazine.  
  • Jim Gates received the 2021 AIP Andrew Gemant Award. He was also profiled in Symmetry Magazine.
  • Carter Hall was featured on the Department of Energy website regarding what his 2011 Early Career Award had meant to his research.
  • Donna Hammer was named a Society of Physics Students Outstanding Chapter Advisor. 
  • Eliot Hammer joined the chair's office as coordinator of administration.
  • Work by Anson Hook was described in Science Daily.
  • Ted Jacobson's idea of a black hole laser was discussed in PhysicsWorld.
  • Danae Johnson joined the department as a business manager.
  • Melanie Knouse received the department's Staff Excellence Award. 
  • Alicia Kollár received a Sloan Research Fellowship.
  • Wolfgang Losert received a Brain and Behavior Institute seed grant award.
  • Howard Milchberg, Daniel Woodbury (Ph.D., '20), Robert Schwartz wrote a Physics Today Quick Study showing how revisiting early experiments with new tech leads to pinpointing individual electrons in ambient gases. 
  • Rabi Mohapatra will retire on August 1, 2022.
  • Allen Monroe received the department's Staff Excellence Award. 
  • Johnpierre Paglione was named an Outstanding Referee of the Physical Review journals.
  • Naomi Russo received the department's Sibylle Sampson Award.
  • Jay Sau was named UMD co-Director of the Joint Quantum Institute.
  • Yasser Saleh joined the department as procurement coordinator.
  • Brian Straughn received the Lorraine DeSalvo Chair's Award for Outstanding Service.
  • Fred Wellstood will retire on April 1, 2022.
  • LaVita Williams joined the payroll office as a business service specialist.
 Students
  • Elizabeth Bennewitz, a graduate student working with Alexey Gorshkov, has been named a finalist for a 2022 Hertz Fellowship.
  • Yonatan Gazit and Yanda Geng received the Richard and Anna Iskraut Award.
  • Donovan Buterakos, Haining Pan, DinhDuy Vu won the Richard E. Prange Graduate Student Award.
  • Sagar Airen received the Kapo-Barwick Award.
  • Batoul Banihashemi, Yan Li, Braden Kronheim, Edward Broadberry, Jeremy Shuler, Subhayan Sahu, Saurabh Kadam, Nathaniel Fried received the Ralph Myers Award
Alumni
  • Vakhtang Agayan (Ph.D., '00) was named Chief Technology Officer of KMK Consulting
  • Beatriz Burrola Gabilondo (Ph.D., '10) was named an APS Equity, Diversion and Inclusion Fellow.
  • Laird Egan, (Ph.D., '21), was quoted in a Physics story on quantum error correction. 
  • Alexei Fedotov (Ph.D. ’97), received teh Dieter Möhl Medal in the field of beam cooling.
  • Salman Habib, Director at Argonne Lab's high energy division was a PhD student of mine (1988).
  • Ruth Kastner received a  Visiting Fellowship at the University of Pittsburgh's Center for Philosophy of Science.
  • Ying-Cheng Lai (Ph.D., '92) was named a Regents Professor at Arizona State University.
  • Thomas Mason, B.S. '89, physics; B.S. '89, electrical engineering  https://www.chemistry.ucla.edu/news/mason-group-research-featured-science-advances  
  • Elizabeth Paul (Ph.D., '20) and Matt Landreman published work on a twisty stellarator in Physical Review Letters.
  • Denjoe O'Connor (Ph.D. '85) is now the Director of Dublin Institute for Advanced Studies, the position Erwin Schrödinger held during World War II.
  • TC Shen (Ph.D. '85) is a professor of physics at Utah State University.
  • Chris Stephens (Ph.D. '86) is the director of the Center for Complexity Science at UNAM, Mexico City.
Book Marks

Victor Yakovenko's work in econophysics was discussed extensively in the book Anthill Economics.

Department Notes 
 
 
 

Thomas Ferbel, 1937- 2022

Thomas Ferbel, a UMD visiting professor since 2013, died at his home on Saturday, March 12. He was 84.

Ferbel was born in 1937 in Radom, Poland. During the tumult of World War II, he and his family endured exile in a Russian gulag and later, a camp for displaced persons in Stuttgart. Eventually, Ferbel arrived in New York and received a B.A. in Chemistry from Queens College, CUNY, and his and Ph.D. in Physics from Yale University (where his favorite professor was Bob Gluckstern, later the chancellor of this campus and a professor of physics).Thomas FerbelThomas Ferbel

After a postdoctoral appointment at Yale, Ferbel accepted a faculty position at the University of Rochester in 1965.  While there, he received an Alfred P. Sloan Fellowship, a John S. Guggenheim Fellowship and an Alexander von Humboldt Prize.

He was elected a Fellow of the American Physical Society in 1984, and served as the U.S. program manager for the Large Hadron Collider from 2004-08.

In 2020, Ferbel described both his early years and his life as a physicist as part of the American Institute of Physics Oral History project. The transcript is available here: https://www.aip.org/history-programs/niels-bohr-library/oral-histories/46304

Bennewitz Named Finalist for Hertz Fellowship

Elizabeth Bennewitz, a first-year physics graduate student at JQI and QuICS, has been named a finalist for a 2022 Hertz Fellowship. Out of more than 650 applicants, Bennewitz is one of 45 finalists with a chance of receiving up to $250,000 in support from the Fannie and John Hertz Foundation.

The fellowships provide up to five years of funding for recipients pursuing a Ph.D. The foundation seeks(link is external) individuals who intend to tackle “major, near-term problems facing society.”Elizabeth Bennewitz (credit:  Dan Spencer)Elizabeth Bennewitz (credit: Dan Spencer)

“This whole group of finalists have accomplished so much, and I’m very humbled to be among other people starting their Ph.D.s who are also pursuing big problems in science,” says Bennewitz. “I'm very honored to be part of this finalist group.”

Bennewitz is working with JQI and QuICS Fellow Alexey Gorshkov and is interested in researching large collections of interacting quantum particles—what scientists call many-body quantum systems. These systems are important to understanding cutting-edge physics and quantum computer technologies and can also be the basis of simulations that could provide insights into complex problems in physics, material science and chemistry.

“During my PhD, I want to develop tools and techniques that help harness the computational power of quantum devices in order to simulate these large quantum many-body systems,” Bennewitz says. “I’m excited to be pursuing this research at Maryland because of its commitment to quantum information and quantum computing research as well as its rich collaboration between theorists and experimentalists.”

Bennewitz is just at the beginning of her graduate student career, but she has already started investigating how quantum simulators might be used to understand the interactions of the particles that are responsible for holding the nuclei of atoms together.

“I'm very happy for Elizabeth, and I'm honored and excited that she chose to work with my group,” Gorshkov says.

An announcement of the winning fellows is expected to be made in May.

“I'm very thankful for all the opportunities I had before I got here,” Bennewitz says. “I would not be where I am today without the support and guidance I received from my professors and peers at Bowdoin College and Perimeter.”

Original story by Bailey Bedford: https://jqi.umd.edu/news/jqi-graduate-student-finalist-hertz-fellowship

Kollár Awarded Sloan Research Fellowship

Assistant Professor Alicia Kollár has been awarded a prestigious 2022 Sloan Research Fellowship. This award is given to early career researchers by the Alfred P. Sloan Foundation to recognize distinguished performance and the potential to make substantial contributions to their field. Each fellowship provides $75,000 to support the fellow’s research over two years.

Kollár will use the fellowship to support her research into creating new synthetic materials that are designed using quantum physics and applied mathematics. These synthetic materials can reveal physics that is difficult or impossible to observe in traditional materials.

“What really excites me about this award is to see support for the more interdisciplinary side of my research,” Kollár says. “My original background is in quantum physics and that's been where my grant support has come from so far, but this Sloan award is focused on looking at questions at the intersection of math and physics.”Alicia Kollár Alicia Kollár

This line of Kollár’s research uses mathematical tools based on the field of graph theory—the study of relationships between objects (in terms of a “graph” made of “vertices” that are connected by “edges”). Researchers use the tools to produce stripped down descriptions of materials in terms of just nodes and their connections—like if there is a connection where electrons can hop between specific points in a material. These descriptions don’t care about the exact distance between atoms or molecules or their precise orientation relative to each other but only about what connections exist between points. This approach is useful for identifying overarching features of different types of materials and is especially helpful in sorting out which material properties are derived from the basic connections being investigated, as opposed to those related to the quirks of a material’s particular components.

This mathematical perspective allows researchers, like Kollár, to design abstract connections that should produce unique properties, but it isn’t easy to then translate the idea on a page into a material that has the exact desired connections. Going from pure math to a real material is much harder than the reverse process of stripping details away from a well-studied material; to do so requires the exhaustive work of recognizing and juggling all the idiosyncrasies of real chemistry. The details of all the possible choices of atoms and how they interact and arrange themselves makes matching the elegant mathematical design to a physical material prohibitively challenging.

So instead Kollár has focused on synthetic materials made of circuits of resonators and superconducting qubits that house traveling microwaves. These circuits easily recreate the flexible connections of graph-theoretic descriptions and can let the complex physics play out, revealing features that current simulations can’t calculate. Essentially, Kollár can custom design the desired connections in a synthetic material and see if the results are interesting instead of going through the hassle of searching for a chemical structure that naturally has the connections every time she wants to do a new experiment. She has even been able to create connections that simulate a negatively curved space—a space impossible to create in the lab because they have “more space” than our normal space.

The insights from these synthetic materials have the potential to reveal new material behaviors and to give researchers a better understanding of how to best use graph-theoretic techniques.

Besides making these synthetic materials she is also working to push the mathematical side of this approach, including identifying new mathematical rules that govern one dimensional graphs that might provide insights into codes used in quantum computing.

 “This Sloan Fellowship will give my group the opportunity to really dig in to optimizing how synthetic materials are made in order to make them as versatile a tool as possible,” Kollár says.

The Sloan fellowships are awarded to untenured teaching faculty who work in the fields of chemistry, computer science, Earth system science, economics, mathematics, neuroscience, physics, or a related field. Candidates are nominated by their colleagues, and then fellows are selected by an independent committee of researchers in the relevant field based on the candidates’ “independent research accomplishments, creativity, and potential to become leaders in the scientific community through their contributions to their field,” according to the Sloan website. Other UMD winners this year are Lei Chen of mathematics and Pratyush Tiwary of chemistry/biochemisty and IPST. 

“Today’s Sloan Research Fellows represent the scientific leaders of tomorrow,” says Adam F. Falk, president of the Alfred P. Sloan Foundation. “As formidable young scholars, they are already shaping the research agenda within their respective fields—and their trailblazing won’t end here.”

 

Original story by Bailey Bedford: https://jqi.umd.edu/news/jqi-fellow-kollar-awarded-sloan-research-fellowship