Andreas Wallraff is a German

physicist A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate cau ...

who conducts research in

quantum information processing Quantum information science is a field that combines the principles of quantum mechanics with information theory to study the processing, analysis, and transmission of information. It covers both theoretical and experimental aspects of quantum phys ...

and

quantum optics Quantum optics is a branch of atomic, molecular, and optical physics and quantum chemistry that studies the behavior of photons (individual quanta of light). It includes the study of the particle-like properties of photons and their interaction ...

. He has taught as a professor at

ETH Zurich ETH Zurich (; ) is a public university in Zurich, Switzerland. Founded in 1854 with the stated mission to educate engineers and scientists, the university focuses primarily on science, technology, engineering, and mathematics. ETH Zurich ran ...

Zurich, Switzerland Zurich (; ) is the largest city in Switzerland and the capital of the canton of Zurich. It is in north-central Switzerland, at the northwestern tip of Lake Zurich. , the municipality had 448,664 inhabitants. The urban area was home to 1.45 ...

since 2006. He worked as a research scientist with Robert J. Schoelkopf at

Yale University Yale University is a Private university, private Ivy League research university in New Haven, Connecticut, United States. Founded in 1701, Yale is the List of Colonial Colleges, third-oldest institution of higher education in the United Stat ...

from 2002 to 2005, during which time he performed experiments in which the coherent interaction of a single photon with a single quantum electronic circuit was observed for the first time.A. Wallraff, D. I. Schuster, A. Blais, L. Frunzio, R.- S. Huang, J. Majer, S. Kumar, S. M. Girvin, and R. J. Schoelkopf, "Strong coupling of a single photon to a superconducting qubit using circuit quantum electrodynamics", ''

Nature Nature is an inherent character or constitution, particularly of the Ecosphere (planetary), ecosphere or the universe as a whole. In this general sense nature refers to the Scientific law, laws, elements and phenomenon, phenomena of the physic ...

'' 431, 162-167 (2004), His current work at ETH Zurich focuses on hybrid quantum systems combining

superconducting Superconductivity is a set of physical properties observed in superconductors: materials where electrical resistance vanishes and magnetic fields are expelled from the material. Unlike an ordinary metallic conductor, whose resistance decreases g ...

electronic circuits An electronic circuit is composed of individual electronic components, such as resistors, transistors, capacitors, inductors and diodes, connected by conductive wires or traces through which electric current can flow. It is a type of electric ...

with

semiconductor A semiconductor is a material with electrical conductivity between that of a conductor and an insulator. Its conductivity can be modified by adding impurities (" doping") to its crystal structure. When two regions with different doping level ...

quantum dots Quantum dots (QDs) or semiconductor nanocrystals are semiconductor particles a few nanometres in size with optical and electronic properties that differ from those of larger particles via quantum mechanical effects. They are a central topic i ...

and individual

Rydberg atoms A Rydberg atom is an excited atom with one or more electrons that have a very high principal quantum number, ''n''. The higher the value of ''n'', the farther the electron is from the nucleus, on average. Rydberg atoms have a number of peculi ...

as well as

quantum error correction Quantum error correction (QEC) is a set of techniques used in quantum computing to protect quantum information from errors due to decoherence and other quantum noise. Quantum error correction is theorised as essential to achieve fault tolerant ...

with

superconducting qubits Superconducting quantum computing is a branch of solid state physics and quantum computing that implements superconducting electronic circuits using superconducting qubits as artificial atoms, or quantum dots. For superconducting qubits, the two ...

. He has contributed primarily to the field of

quantum information science Quantum information science is a field that combines the principles of quantum mechanics with information theory to study the processing, analysis, and transmission of information. It covers both theoretical and experimental aspects of quantum phys ...

, particularly in

superconducting quantum computing Superconducting quantum computing is a branch of Solid-state physics, solid state physics and quantum computing that implements superconductivity, superconducting electronic circuits using superconducting qubits as artificial atoms, or quantum dot ...

and hybrid quantum systems.

Education and earlier work

Andreas Wallraff obtained his undergraduate degrees in physics from

Imperial College London Imperial College London, also known as Imperial, is a Public university, public research university in London, England. Its history began with Prince Albert of Saxe-Coburg and Gotha, Prince Albert, husband of Queen Victoria, who envisioned a Al ...

and

RWTH Aachen University RWTH Aachen University (), in German ''Rheinisch-Westfälische Technische Hochschule Aachen'', is a German public research university located in Aachen, North Rhine-Westphalia, Germany. With more than 47,000 students enrolled in 144 study prog ...

and conducted research on

soliton In mathematics and physics, a soliton is a nonlinear, self-reinforcing, localized wave packet that is , in that it preserves its shape while propagating freely, at constant velocity, and recovers it even after collisions with other such local ...

dynamics in stacked Josephson tunnel junctions for his master's degree at the

Forschungszentrum Jülich Forschungszentrum Jülich (FZJ; “Jülich Research Centre”) is a German national research institution that pursues interdisciplinary research in the fields of energy, information, and bioeconomy. It operates a broad range of research infrast ...

and RWTH Aachen, which he earned in 1997. During his doctoral research on soliton and vortex dynamics in superconductors at the

University of Erlangen-Nuremberg A university () is an institution of tertiary education and research which awards academic degrees in several academic disciplines. ''University'' is derived from the Latin phrase , which roughly means "community of teachers and scholars". Univ ...

, he observed for the first time the tunneling and energy level quantization of an individual

quantum vortex In physics, a quantum vortex represents a quantized flux circulation of some physical quantity. In most cases, quantum vortices are a type of topological defect exhibited in superfluids and superconductors. The existence of quantum vortices was ...

for which he obtained a PhD degree in physics in 2000. Following his doctoral research, Wallraff continued to work as a research scientist and later as an assistant professor at the University of Erlangen-Nuremberg. In 2002, he left Europe to work as a postdoctoral researcher with Robert J. Schoelkopf within the Department of Applied Physics at Yale University in

New Haven, Connecticut New Haven is a city of the U.S. state of Connecticut. It is located on New Haven Harbor on the northern shore of Long Island Sound. With a population of 135,081 as determined by the 2020 United States census, 2020 U.S. census, New Haven is List ...

. During this time, he was an author on papers regarding the coupling of superconducting

qubits In quantum computing, a qubit () or quantum bit is a basic unit of quantum information—the quantum version of the classic binary bit physically realized with a two-state device. A qubit is a two-state (or two-level) quantum-mechanical system, ...

via a

cavity Cavity may refer to: Biology and healthcare *Body cavity, a fluid-filled space in many animals where organs typically develop **Gastrovascular cavity, the primary organ of digestion and circulation in cnidarians and flatworms *Dental cavity or too ...

bus A bus (contracted from omnibus, with variants multibus, motorbus, autobus, etc.) is a motor vehicle that carries significantly more passengers than an average car or van, but fewer than the average rail transport. It is most commonly used ...

and the coherent interaction of a single photon to a

Cooper-pair box In quantum computing, a charge qubit (also known as Cooper-pair box) is a qubit whose basis states are charge states (i.e. states which represent the presence or absence of excess Cooper pairs in the island). In superconducting quantum computing, ...

, among others. In 2004 he was appointed as an associate research scientist in the Department of Applied Physics at Yale and in June 2005 he was elected as a tenure-track assistant professor at ETH Zurich. Following the professorship appointment, he departed from Yale and started the Quantum Device Lab at ETH Zurich in January 2006. In 2011, he was chosen from among 380 ETH Zurich professors to be awarded the Max Rössler Prize for his research activities. In 2012, he worked as a visiting professor at the Kastler-Brossel Laboratory within the

École Normale Supérieure École or Ecole may refer to: * an elementary school in the French educational stages normally followed by Secondary education in France, secondary education establishments (collège and lycée) * École (river), a tributary of the Seine flowing i ...

Paris, France Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, largest city of France. With an estimated population of 2,048,472 residents in January 2025 in an area of more than , Paris is the List of ci ...

Research topics

Wallraff has in recent years been studying a variety of topics related to quantum information science. Among them include interactions between distant artificial atoms, quantum

many-body The many-body problem is a general name for a vast category of physical problems pertaining to the properties of microscopic systems made of many interacting particles. Terminology ''Microscopic'' here implies that quantum mechanics has to be ...

systems, digital

quantum simulation Quantum simulators permit the study of a quantum system in a programmable fashion. In this instance, simulators are special purpose devices designed to provide insight about specific physics problems. Note: This manuscript is a contribution o ...

quantum nonlocality In theoretical physics, quantum nonlocality refers to the phenomenon by which the measurement statistics of a multipartite quantum system do not allow an interpretation with local realism. Quantum nonlocality has been experimentally verified unde ...

, the implementation of the

Toffoli gate In logic circuits, the Toffoli gate, also known as the CCNOT gate (“controlled-controlled-not”), invented by Tommaso Toffoli in 1980 is a CNOT gate with two control bits and one target bit. That is, the target bit (third bit) will be inver ...

in quantum computation,

deterministic Determinism is the metaphysical view that all events within the universe (or multiverse) can occur only in one possible way. Deterministic theories throughout the history of philosophy have developed from diverse and sometimes overlapping mo ...

quantum teleportation Quantum teleportation is a technique for transferring quantum information from a sender at one location to a receiver some distance away. While teleportation is commonly portrayed in science fiction as a means to transfer physical objects from on ...

, and the Hong-Ou-Mandel effect. In general, his research is primarily focused on investigating

circuit QED Circuit quantum electrodynamics (circuit QED) provides a means of studying the fundamental interaction between light and matter (quantum optics). As in the field of cavity quantum electrodynamics, a single photon within a single mode cavity coher ...

(cQED) systems and their applications in

. These include implementing

quantum gates In quantum computing and specifically the quantum circuit model of computation, a quantum logic gate (or simply quantum gate) is a basic quantum circuit operating on a small number of qubits. Quantum logic gates are the building blocks of quantu ...

, identifying and eliminating sources of

quantum decoherence Quantum decoherence is the loss of quantum coherence. It involves generally a loss of information of a system to its environment. Quantum decoherence has been studied to understand how quantum systems convert to systems that can be expla ...

to extend qubit lifetimes, and creating solid-state architectures in which

is possible. In addition, he conducts research into "hybrid quantum systems"; cQED systems interacting with

and

to combine "the long coherence times available in microscopic quantum systems with the strong interactions and integration available in solid state systems... o allowfor strong interactions with control fields and thus fast manipulation of the

quantum state In quantum physics, a quantum state is a mathematical entity that embodies the knowledge of a quantum system. Quantum mechanics specifies the construction, evolution, and measurement of a quantum state. The result is a prediction for the system ...

of a system." His research has been honoured with multiple awards, such as the ETH Zurich's Rössler-Prize in 2013 and the Helmholtz International Fellow Award in 2020.

Positions and speaking engagements

Since January 2006, Wallraff has held a professorship position at ETH Zurich where he is the head of the Quantum Device Lab within the Laboratory for Solid State Physics. He has been awarded several grants, including two from the

European Research Council The European Research Council (ERC) is a public body for funding of scientific and technological research conducted within the European Union (EU). Established by the European Commission in 2007, the ERC is composed of an independent Scientific ...

(one in 2009 for hybrid

cavity quantum electrodynamics Cavity Quantum Electrodynamics (cavity QED) is the study of the interaction between light confined in a reflective cavity and atoms or other particles, under conditions where the quantum nature of photons is significant. It could in principle be ...

and one in 2013 for superconducting quantum networks) and holds positions as the President of the Strategy Commission for the Department of Physics and Deputy Head of the Laboratory for Solid State Physics at ETH Zurich. He is also a member of the Scientific Committee for the

Swiss National Science Foundation The Swiss National Science Foundation (SNSF, German: , SNF; French: , FNS; Italian: ) is a science research support organisation mandated by the Swiss Federal Government. The Swiss National Science Foundation was established under private law b ...

National Center of Competence in Research (NCCR) in Quantum Science and Technology (QSIT), a member of the Global Future Council for the Future of Computing at the

World Economic Forum The World Economic Forum (WEF) is an international non-governmental organization, international advocacy non-governmental organization and think tank, based in Cologny, Canton of Geneva, Switzerland. It was founded on 24 January 1971 by German ...

, and an Associate Fellow of the

Canadian Institute for Advanced Research The Canadian Institute for Advanced Research (CIFAR) is a Canadian-based global research organization that brings together teams of top researchers from around the world to address important and complex questions. It was founded in 1982 and is su ...

. Wallraff has been an invited speaker at several talks and conferences, including at the inaugural celebration for the Center for Quantum Coherence Science at the

University of California, Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California), is a Public university, public Land-grant university, land-grant research university in Berkeley, California, United States. Founded in 1868 and named after t ...

The Optical Society Optica, founded as the Optical Society of America (later the Optical Society), is a professional society of individuals and companies with an interest in optics and photonics. It publishes journals, organizes conferences and exhibitions, and ca ...

"Quantum Information and Measurement - Quantum Technologies" meeting at the

Pierre and Marie Curie University Pierre and Marie Curie University ( , UPMC), also known as Paris VI, was a public research university in Paris, France, from 1971 to 2017. The university was located on the Jussieu Campus in the Latin Quarter of the 5th arrondissement of Paris, ...

, the IWQD 2017 workshop at the

National Institute of Informatics The is a Japanese research institute located in Chiyoda, Tokyo, Chiyoda, Tokyo, Japan. NII was established in April 2000 for the purpose of advancing the study of Informatics (academic field), informatics. This institute also works on creatin ...

, and the 635th WE

Heraeus Heraeus is a German technology group with a focus on precious and special metals, medical technology, quartz glass and sensors as well as electronic components. Founded in Hanau in 1851, the company is one of the largest family-owned companies ...

Seminar in 2017. In 2016 he spoke at the

Institute of Physics The Institute of Physics (IOP) is a UK-based not-for-profit learned society and professional body that works to advance physics education, physics research, research and applied physics, application. It was founded in 1874 and has a worldwide ...

Silicon Quantum Information Processing meeting at

Murray Edwards College, Cambridge Murray Edwards College is a women-only constituent college of the University of Cambridge. It was founded in 1954 as New Hall and renamed in 2008. The name honours a gift of £30 million by alumna Ros Edwards and her husband Steve, and the firs ...

, the

University of Science and Technology of China The University of Science and Technology of China (USTC) is a public university in Hefei, China. It is affiliated with the Chinese Academy of Sciences, and co-funded by the Chinese Academy of Sciences, the Ministry of Education of the People' ...

, and the SCALEQIT International Conference at the

Delft University of Technology The Delft University of Technology (TU Delft; ) is the oldest and largest Dutch public university, public Institute of technology, technical university, located in Delft, Netherlands. It specializes in engineering, technology, computing, design, a ...

. In previous years he also spoke at the

University of Oxford The University of Oxford is a collegiate university, collegiate research university in Oxford, England. There is evidence of teaching as early as 1096, making it the oldest university in the English-speaking world and the List of oldest un ...

, the

Max Planck Institute for the Science of Light The Max Planck Institute for the Science of Light (MPL) performs basic research in optical metrology, optical communication, new optical materials, plasmonics and nanophotonics and optical applications in biology and medicine. It is part of the ...

, the Institute for Theoretical Atomic Molecular and Optical Physics (ITAMP) 2015 workshop at

Harvard University Harvard University is a Private university, private Ivy League research university in Cambridge, Massachusetts, United States. Founded in 1636 and named for its first benefactor, the History of the Puritans in North America, Puritan clergyma ...

, and the

Kavli Institute for Theoretical Physics The Kavli Institute for Theoretical Physics (KITP) is a research institute of the University of California, Santa Barbara dedicated to theoretical physics. KITP is one of 20 Kavli Foundation (United_States)#The Kavli Institutes, Kavli Institutes ...

at the

University of California, Santa Barbara The University of California, Santa Barbara (UC Santa Barbara or UCSB) is a Public university, public Land-grant university, land-grant research university in Santa Barbara County, California, United States. Tracing its roots back to 1891 as an ...

References

External links

Quantum Device Lab Website

Quantum Device Lab on Twitter
{{DEFAULTSORT:Wallraff, Andreas German quantum physicists Quantum information scientists 21st-century German physicists Academic staff of ETH Zurich RWTH Aachen University alumni Alumni of Imperial College London Year of birth missing (living people) Living people German expatriates in Switzerland