Quantum computing

Interview with Michel Devoret, the Frederick W. Beinecke Professor of Applied Physics and Director of the Applied Physics Nanofabrication Lab at Yale University. Devoret recounts his childhood in France where his father was a physician and his mother was a teacher. He describes his parents’ experiences during World War II and his early interests in many areas of science such as computers, artificial intelligence, and biology. Devoret explains some nuances of the French schooling system and how he followed an engineering track in his undergraduate studies before focusing on physics. He recalls pursuing his Master’s degree at Orsay University where he worked in a molecular physics lab, as well as the opportunity that led him to pursue a PhD while working in Anatole Abragam’s lab at the Atomic Energy Commission (CEA) in Saclay. Devoret talks about his thesis work on nuclear magnetic resonance in solid hydrogen. He then discusses his postdoc at Berkeley working with John Clarke on quantum tunneling and his subsequent return to Saclay where he eventually helped found the Quantonics Lab and later was named Director of Research at CEA-Saclay. Devoret recalls the circumstances around his move to Yale and his work with Steve Girvin. He reflects on several of his interest areas during this time, such as microwave reflectometry, nanofabrication, remote entanglement, and quantum computing. At the end of the interview, Devoret offers advice for how to avoid doing bad science, and he shares his recent interest in the popularization of science, particularly making quantum physics more accessible.

Interview with Dale Van Harlingen, Professor of Physics at the University of Illinois, Urbana-Champaign. He recounts his childhood in Ohio and his undergraduate education at OSU in physics and his early work on SQUIDS. Van Harlingen discusses his mentor Jim Garland, and he explains his decision to stay at OSU for graduate school to develop SQUID devices to make phase-sensitive measurements. He explains the opportunities that gained him a postdoctoral appointment at the Cavendish Laboratory in Cambridge where he developed his expertise in the Josephson Effect, and where he met John Clarke, who offered him a subsequent postdoctoral position at UC Berkeley. Van Harlingen describes his foray using SQUIDS to push the quantum limit, and he explains his decision to join the faculty at Illinois, where he was impressed both with the quality of the research and how nice everyone was. He describes joining the Materials Research Laboratory and the development of the Micro and Nanotechnology Laboratory, and he conveys his admiration for Tony Leggett. Van Harlingen discusses his research in NMR microscopy, grain boundary junctions, scanning tunneling microscopy, vortex configurations, and he describes his current interest in unconventional superconductors. At the end of the interview, Van Harlingen conveys his excitement about the national quantum initiative as a major collaboration between universities and National Labs, and he explains his motivation to understand if Majorana fermions actually exist.

Interview with Peter W. Shor, Morss Professor of Applied Math at MIT. Shor recounts his childhood in Brooklyn and then Washington, DC, and he describes his discovery early in childhood that he had a special aptitude in math. He describes his undergraduate experience at Caltech, where he pursued an interest in combinatronics, and he explains his decision to attend MIT for graduate school, where he studied under Tom Leighton. Shor discusses his graduate work at Bell Labs and he explains how applied math research was relevant to Bell's business model. He describes his thesis research which used math to design good algorithms for computer problem solving, and he discusses his postdoctoral research at the Mathematical Science Research Institute at Berkeley where he focused on computational geometry problems. Shor explains his decision to return to Bell Labs and his focus on optical fibers, and he explains Google's influence in achieving breakthroughs in theoretical computer science. He describes the origins of Shor's Algorithm and Charles Bennett's involvement in this development. Shor explains when true quantum computing became theoretically feasible, and the various budgetary, theoretical, and political challenges that stand between the current state of play and quantum computer realization. He explains his interest in returning to academia at the time Bell Labs was coming apart, and he explains his contributions to advancing quantum information and the utility this has for AdS/CFT research. Shor describes his current interest in black holes and quantum money, and at the end of the interview, he explains why the question of whether NP = P remains fundamental.

Interview with Charles H. Bennett, IBM Fellow and Research Staff Member at the Thomas J. Watson Research Center, IBM Corporation. Bennett recounts his childhood in the Hudson Valley, and he describes his exposure to the earliest versions of computers. He explains that his first interest as an undergraduate at Brandeis was in biochemistry, and how his focus shifted to chemical physics by the time he became a graduate student at Harvard where he studied under David Turnbull. Bennett discusses his postdoctoral research with Aneesur Rahman at Argonne National Laboratory and his growing interest in using computers for data analysis. He describes the opportunity that led to his job offer at IBM and he surveys the field of quantum information in its earliest formation. Bennett discusses his involvement in quantum cryptography and its relation to the uncertainty principle. He explains the origins of quantum teleportation, and he reflects on some of the central mysteries of quantum mechanics. Bennett discusses his work on entanglement distillation, and he describes some of the early naysaying about quantum computation. He surveys his more recent interests in the quantum reverse Shannon theorem and rediscovering rate distortion theory. At the end of the interview, Bennett puts some of the “buzz” regarding quantum computing in historical perspective and he explains his interest in applying mathematical models to understand questions about equilibrium in cosmology.

In this interview, Gia Dvali discusses: current interests in the physics of black holes and their capacity to store information; learning about black holes by examining and observing the universal underlying physics of other seemingly unrelated saturated systems or “saturons”; development of a theory of a black hole as a composite object; ability to produce saturated systems in a laboratory; papers about trying to understand a black hole as a neural network, ideas of using black hole information storage and processing mechanisms in quantum computing; process of how one quantifies the information capacity of a black hole using the micro-state entropy of an object; connection between black hole research and understanding the universe as a saturated system with area entropy; unitarity and maximal entropy; research on de Sitter space and the cosmological constant puzzle; ultraviolet sensitivity; Einstein gravity and the Planck length; naturalness as a guideline to making breakthroughs. 

Interview with Lu Sham, Distinguished Professor of Physics Emeritus, University of California at San Diego. Sham recounts his childhood in Hong Kong and he describes the legacy of Japanese rule from World War II. He describes his early interests in math and he explains his decision to pursue a higher education in England at Imperial College. Sham discusses his motivation to conduct graduate work at Cambridge University and to study under Nevill Mott on the first principle method calculating the electron contribution to lattice vibration. He describes the help provided by John Ziman to secure his postdoctoral position at UC San Diego to work with Walter Kohn, and he describes the foundational collaboration and research that went into the Kohn-Sham equation and how this work builds on the classic debate between Einstein and Bohr. He describes the opportunities leading to his faculty appointment and eventual tenure on the physics faculty, and he explains the benefits of spending summers doing research at Bell Labs. Sham discusses his contributions to research on semiconductors, quantum computing, and density-functional theory. He describes his more recent interest in optics and the formative work he has done with graduate students and postdoctoral researchers over the years. Sham discusses his administrative service as department chair and Dean of Science. At the end of the interview, Sham asserts that the future of condensed matter physics holds limitless possibilities, and that improvements in semiconductor materials will push quantum information abilities in exciting and unforeseen directions.

Interview with John Preskill, Richard P. Feynman Professor of Theoretical Physics at Caltech, and Director of the Institute for Quantum Information and Matter at Caltech. Preskill describes the origins of IQIM as a research pivot from the initial excitement in the 1970s to move beyond Standard Model physics and to understand the origin of electroweak symmetry breaking. He emphasizes the importance of Shor’s algorithm and the significance of bringing Alexei Kitaev into the project. Preskill discusses the support he secured from the NSF and DARPA, and he recounts his childhood in Chicago and his captivation with the Space Race. He describes his undergraduate experience at Princeton and his relationship with Arthur Wightman and John Wheeler. Preskill explains his decision to pursue his thesis research at Harvard with the intention of working with Sidney Coleman, and he explains the circumstances that led to Steve Weinberg becoming his advisor. He discusses the earliest days of particle theorists applying their research to cosmological inquiry, his collaboration with Michael Peskin, and his interest in the connection of topology with particle physics. Preskill describes his research on magnetic monopoles, and the relevance of condensed matter theory for his interests. He explains the opportunities that led to his appointment to the Harvard Society of Fellows and his eventual faculty appointment at Harvard, his thesis work on technicolor, and the excitement surrounding inflation in the early 1980s. Preskill discusses the opportunities that led to his tenure at Caltech and why he started to think seriously about quantum information and questions relating to thermodynamic costs to computing. He explains the meaning of black hole information, the ideas at the foundation of Quantum Supremacy, and he narrates the famous story of the Thorne, Hawking, and Preskill bets. Preskill describes the advances in quantum research which compelled him to add “matter” to the original IQI project which was originally a purely theoretical endeavor. He discusses the fact that end uses for true quantum computing remain open questions, and he surveys IQIM’s developments over the past decade and the strategic partnerships he has pursued across academia, industry, and at the National Labs. Preskill surveys the potential value of quantum computing to help solve major cosmological mysteries, and why his recent students are captivated by machine learning. At the end of the interview, Preskill reflects on his intersecting interests and conveys optimism for future progress in understanding quantum gravity from laboratory experiments using quantum simulators and quantum gravity.

Interview with William "Bill" Unruh, Professor of Physics and Astronomy at the University of British Columbia, and Hagler Fellow at the Institute for Quantum Science and Engineering at Texas A&M. He credits his mentor John Wheeler for the steady progress of interest and work in general relativity over the decades, and he reflects broadly on the original debates among the relativists and the founders of quantum mechanics. Unruh explains the inability to merge these foundations of physics as the source of his attempts to understand the black hole evaporation as found by Hawking. He recounts his upbringing in Manitoba as part of a Mennonite community and his early interests in Euclidean geometry, and he describes his undergraduate education at the University of Manitoba. Unruh explains his decision to pursue a PhD with Wheeler at Princeton on topology and general relativity, and scattering cross sections of black holes to scalar fields. He describes his postgraduate appointment at Birkbeck College where he worked with Roger Penrose and he narrates the origins of his collaboration with Stephen Fulling and Paul Davies. Unruh discusses his time at Berkeley and then at McMaster and he historicizes the point at which observations made black holes more "real," and he explains his first involvement with decoherence. He explains his involvement with LIGO from its origins and its quantum mechanical nature, and he narrates his reaction of amazement when gravitational waves were detected. Unruh describes the impact of his work in quantum mechanics on computation, and he explains some of the advances that have made observation more relevant to his recent research. At the end of the interview, Unruh describes his efforts to launch a Gravity Archive at UBC, he expresses his frustration with people who insist we do not know quantum mechanics, and he quotes Wheeler, quoting his favorite Grook to convey that he is having fun and wants to learn as much as he can, while he can.

Interview with Ana Maria Rey, Professor Adjoint at the University of Colorado at Boulder, and a fellow at NIST and JILA. Rey describes the nature of this tri-appointment, and she discusses some of the difficulties in keeping up her research during the pandemic. She recounts her childhood in Colombia and her early education in an all-girls school and her undergraduate education at the University of Los Andes in physics and the opportunities leading to her acceptance to the University of Maryland for graduate school. Rey describes joining Charles Clark’s group that was focused on modeling ultra-cold atoms, and she explains her initial work at NIST.  She explains her decision to take an initial postdoctoral position at NIST before joining ITAMP at Harvard, where she focused on developing improved models to study the behavior of atoms trapped in crystals of light. Rey describes the opportunities that led to her appointments in Colorado, and her subsequent interests in metrology, the quantum advantage, and trapping molecules. She explains how it felt to be named a MacArthur Fellow and why it is important for her to interact with experimentalists in the quest to build better atomic clocks. Rey explains her efforts to create dark matter detectors and how she hopes that her work on quantum matter will help bring about quantum computers.  She provides her perspective on how to advance diversity and inclusivity in the field, and she delineates her research interests as they pertain to basic science and applications. At the end of the interview, Rey conveys optimism that her research will make advances to the broader understanding of the quantum world.

Interview with Michael Green, Lucasian Professor Emeritus at Cambridge University and visiting professor at Queen Mary University. He recounts his childhood in London as the child of secular Jewish parents who immigrated to London just before World War II. Green discusses his early interests in physics and the opportunities that led to his enrollment at Cambridge, and he conveys Geoff Chew’s influence with his ideas on S-matrix and bootstrap theory, which informed his thesis research on hadronic interactions. He narrates the founding ideas that led to string theory and how the work on dual models became transformed into string theory. Green describes his postdoctoral work at the Institute for Advanced Study and his interactions with Veneziano. He explains his decision to return to Cambridge and the importance of the CERN theory group for his research, and he narrates the origins of his collaborations with John Schwarz. Green connects string theory to the ideas that led to supergravity, and he explains why he does not like the term “revolution” in relation to advances in string theory to explain what was happening between 1981-1984. He explains the meaning of the pronoun “super” in relation to string theory, and he conveys his disappointment that supersymmetry has yet to be observed. Green describes the importance of AdS/CFT and his contributions to the origins of D-branes with Joe Polchinski. He discusses his increasing reliance on computers for understanding aspects of AdS/CFT correspondence. Green reflects on winning the Breakthrough Prize, and the supposed aspirational recognition on working to unify the forces which are not yet unified, and he discusses the generational de-coupling of string theory education from particle physics. He provides sociological perspective in response to the impatience that certain physicists have expressed regarding string theory. At the end of the interview, Green ponders the future relationship between string theory and quantum computing, and he describes the field as an intellectual adventure which makes it difficult to predict the significance of these changes.