John M. Martinis

Last updated
John M. Martinis
Alma mater University of California, Berkeley (B.S., Ph.D.)
Awards Fritz London Memorial Prize, 2014 [1] John Stewart Bell Prize, 2021 [2]
Scientific career
Thesis Macroscopic quantum tunneling and energy-level quantization in the zero voltage state of the current-biased Josephson junction [3]  (1985)
Doctoral advisor John Clarke [3]

John M. Martinis (born 1958) is an American physicist and a professor of physics at the University of California, Santa Barbara. In 2014, the Google Quantum A.I. Lab announced that it had hired Martinis and his team in a multimillion dollar deal to build a quantum computer using superconducting qubits. [4]

Career

John Martinis (2017)

John M. Martinis received his B.S. in physics in 1980 and his Ph.D. in physics from the University of California, Berkeley. During his Ph.D., he investigated the quantum behaviour of a macroscopic variable, the phase difference across a Josephson tunnel junction. [5]

He joined the Commissariat à l'Energie Atomique in Saclay, France, for a first postdoc and then the Electromagnetic Technology division at the National Institute of Standards and Technology (NIST) in Boulder, where he worked on superconducting quantum interference devices (SQUIDs) amplifiers. [6] While at NIST he developed a technique of X-ray detection by using a superconducting transition-edge sensor microcalorimeter with electrothermal feedback. [7]

Since 2002 he has been working with Josephson-Junction qubits with the aim of building the first quantum computer. [8]

In 2004 he moved to the University of California Santa Barbara, where he held the Worster Chair in experimental physics until 2017. In 2014, Martinis and his team were hired by Google to build the first useful quantum computer. [9]

On October 23, 2019, Martinis and his team published a paper on Nature with title "Quantum supremacy using a programmable superconducting processor", [10] where they presented how they achieved quantum supremacy (hereby disproving the extended Church–Turing thesis) for the first time using a 53-qubits quantum computer. [11] In April 2020 Martinis resigned from Google after being reassigned to an advisory role. [12] [9]

On September 29, 2020, it was announced that Martinis had moved to Australia to join Silicon Quantum Computing, a start-up founded by Professor Michelle Simmons. [13]

In 2022 he co-founded the company Qolab based on the premise that "that the semiconductor industry holds the key to creating a practical quantum computer by enabling the large-scale fabrication of high-quality qubits". As of January 2025 he is the CTO of the company. [14]

In 2021, he received the John Stewart Bell Prize for Research on Fundamental Issues in Quantum Mechanics and Their Applications. [2]

Related Research Articles

<span class="mw-page-title-main">Quantum computing</span> Computer hardware technology that uses quantum mechanics

A quantum computer is a computer that exploits quantum mechanical phenomena. On small scales, physical matter exhibits properties of both particles and waves, and quantum computing leverages this behavior using specialized hardware. Classical physics cannot explain the operation of these quantum devices, and a scalable quantum computer could perform some calculations exponentially faster than any modern "classical" computer. Theoretically a large-scale quantum computer could break some widely used encryption schemes and aid physicists in performing physical simulations; however, the current state of the art is largely experimental and impractical, with several obstacles to useful applications.

<span class="mw-page-title-main">SQUID</span> Type of magnetometer

A SQUID is a very sensitive magnetometer used to measure extremely weak magnetic fields, based on superconducting loops containing Josephson junctions.

<span class="mw-page-title-main">Timeline of quantum computing and communication</span>

This is a timeline of quantum computing.

The magnetic flux, represented by the symbol Φ, threading some contour or loop is defined as the magnetic field B multiplied by the loop area S, i.e. Φ = B ⋅ S. Both B and S can be arbitrary, meaning that the flux Φ can be as well but increments of flux can be quantized. The wave function can be multivalued as it happens in the Aharonov–Bohm effect or quantized as in superconductors. The unit of quantization is therefore called magnetic flux quantum.

<span class="mw-page-title-main">Josephson effect</span> Quantum physical phenomenon

In physics, the Josephson effect is a phenomenon that occurs when two superconductors are placed in proximity, with some barrier or restriction between them. The effect is named after the British physicist Brian Josephson, who predicted in 1962 the mathematical relationships for the current and voltage across the weak link. It is an example of a macroscopic quantum phenomenon, where the effects of quantum mechanics are observable at ordinary, rather than atomic, scale. The Josephson effect has many practical applications because it exhibits a precise relationship between different physical measures, such as voltage and frequency, facilitating highly accurate measurements.

<span class="mw-page-title-main">Charge qubit</span> Superconducting qubit implementation

In quantum computing, a charge qubit is a qubit whose basis states are charge states. In superconducting quantum computing, a charge qubit is formed by a tiny superconducting island coupled by a Josephson junction to a superconducting reservoir. The state of the qubit is determined by the number of Cooper pairs that have tunneled across the junction. In contrast with the charge state of an atomic or molecular ion, the charge states of such an "island" involve a macroscopic number of conduction electrons of the island. The quantum superposition of charge states can be achieved by tuning the gate voltage U that controls the chemical potential of the island. The charge qubit is typically read-out by electrostatically coupling the island to an extremely sensitive electrometer such as the radio-frequency single-electron transistor.

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 logic states are the ground state and the excited state, denoted respectively. Research in superconducting quantum computing is conducted by companies such as Google, IBM, IMEC, BBN Technologies, Rigetti, and Intel. Many recently developed QPUs use superconducting architecture.

<span class="mw-page-title-main">Flux qubit</span> Superconducting qubit implementation

In quantum computing, more specifically in superconducting quantum computing, flux qubits are micrometer sized loops of superconducting metal that is interrupted by a number of Josephson junctions. These devices function as quantum bits. The flux qubit was first proposed by Terry P. Orlando et al. at MIT in 1999 and fabricated shortly thereafter. During fabrication, the Josephson junction parameters are engineered so that a persistent current will flow continuously when an external magnetic flux is applied. Only an integer number of flux quanta are allowed to penetrate the superconducting ring, resulting in clockwise or counter-clockwise mesoscopic supercurrents in the loop to compensate a non-integer external flux bias. When the applied flux through the loop area is close to a half integer number of flux quanta, the two lowest energy eigenstates of the loop will be a quantum superposition of the clockwise and counter-clockwise currents. The two lowest energy eigenstates differ only by the relative quantum phase between the composing current-direction states. Higher energy eigenstates correspond to much larger (macroscopic) persistent currents, that induce an additional flux quantum to the qubit loop, thus are well separated energetically from the lowest two eigenstates. This separation, known as the "qubit non linearity" criteria, allows operations with the two lowest eigenstates only, effectively creating a two level system. Usually, the two lowest eigenstates will serve as the computational basis for the logical qubit.

<span class="mw-page-title-main">D-Wave Systems</span> Canadian quantum computing company

D-Wave Quantum Systems Inc. is a quantum computing company with locations in Palo Alto, California and Burnaby, British Columbia. D-Wave claims to be the world's first company to sell computers that exploit quantum effects in their operation. D-Wave's early customers include Lockheed Martin, the University of Southern California, Google/NASA, and Los Alamos National Laboratory.

A macroscopic quantum state is a state of matter in which macroscopic properties, such as mechanical motion, thermal conductivity, electrical conductivity and viscosity, can be described only by quantum mechanics rather than merely classical mechanics. This occurs primarily at low temperatures where little thermal motion is present to mask the quantum nature of a substance.

<span class="mw-page-title-main">Hartmut Neven</span> German scientist

Hartmut Neven is a German American scientist working in quantum computing, computer vision, robotics and computational neuroscience. He is best known for his work in face and object recognition and his contributions to quantum machine learning. He is currently Vice President of Engineering at Google where he leads the Quantum Artificial Intelligence Lab, which he founded in 2012.

In quantum computing, and more specifically in superconducting quantum computing, the phase qubit is a superconducting device based on the superconductor–insulator–superconductor (SIS) Josephson junction, designed to operate as a quantum bit, or qubit.

The superconducting tunnel junction (STJ) – also known as a superconductor–insulator–superconductor tunnel junction (SIS) – is an electronic device consisting of two superconductors separated by a very thin layer of insulating material. Current passes through the junction via the process of quantum tunneling. The STJ is a type of Josephson junction, though not all the properties of the STJ are described by the Josephson effect.

<span class="mw-page-title-main">Transmon</span> Superconducting qubit implementation

In quantum computing, and more specifically in superconducting quantum computing, a transmon is a type of superconducting charge qubit designed to have reduced sensitivity to charge noise. The transmon was developed by Robert J. Schoelkopf, Michel Devoret, Steven M. Girvin, and their colleagues at Yale University in 2007. Its name is an abbreviation of the term transmission line shunted plasma oscillation qubit; one which consists of a Cooper-pair box "where the two superconductors are also [capacitively] shunted in order to decrease the sensitivity to charge noise, while maintaining a sufficient anharmonicity for selective qubit control".

Macroscopic quantum phenomena are processes showing quantum behavior at the macroscopic scale, rather than at the atomic scale where quantum effects are prevalent. The best-known examples of macroscopic quantum phenomena are superfluidity and superconductivity; other examples include the quantum Hall effect, Josephson effect and topological order. Since 2000 there has been extensive experimental work on quantum gases, particularly Bose–Einstein condensates.

Superconducting logic refers to a class of logic circuits or logic gates that use the unique properties of superconductors, including zero-resistance wires, ultrafast Josephson junction switches, and quantization of magnetic flux (fluxoid). As of 2023, superconducting computing is a form of cryogenic computing, as superconductive electronic circuits require cooling to cryogenic temperatures for operation, typically below 10 kelvin. Often superconducting computing is applied to quantum computing, with an important application known as superconducting quantum computing.

<span class="mw-page-title-main">Michel Devoret</span> French physicist at Yale University

Michel Devoret is a French physicist and F. W. Beinecke Professor of Applied Physics at Yale University. He also holds a position as the Director of the Applied Physics Nanofabrication Lab at Yale. He is known for his pioneering work on macroscopic quantum tunneling, and the single-electron pump as well as in groundbreaking contributions to initiating the fields of circuit quantum electrodynamics and quantronics.

<span class="mw-page-title-main">Yasunobu Nakamura</span> Japanese physicist

Yasunobu Nakamura (中村 泰信 Nakamura Yasunobu) is a Japanese physicist. He is a professor at the University of Tokyo's Research Center for Advanced Science and Technology (RCAST) and the Principal Investigator of the Superconducting Quantum Electronics Research Group (SQERG) at the Center for Emergent Matter Science (CEMS) within RIKEN. He has contributed primarily to the area of quantum information science, particularly in superconducting quantum computing and hybrid quantum systems.

In quantum computing, quantum supremacy or quantum advantage is the goal of demonstrating that a programmable quantum computer can solve a problem that no classical computer can solve in any feasible amount of time, irrespective of the usefulness of the problem. The term was coined by John Preskill in 2011, but the concept dates to Yuri Manin's 1980 and Richard Feynman's 1981 proposals of quantum computing.

Dale J. Van Harlingen was an American condensed matter physicist.

References

  1. ↑ "Fritz London Memorial Prize". phy.duke.edu. Retrieved 21 April 2020.
  2. 1 2 "John Stewart Bell Prize" . Retrieved 3 May 2021.
  3. 1 2 "Physics Tree - John M. Martinis". academictree.org. Retrieved 21 April 2020.
  4. ↑ Finley, Klint (2014-09-05). "The Man Who Will Build Google's Elusive Quantum Computer". Wired. ISSN   1059-1028 . Retrieved 2019-11-02.
  5. ↑ Clarke, J.; Cleland, A. N.; Devoret, M. H.; Esteve, D.; Martinis, J. M. (1988-02-26). "Quantum mechanics of a macroscopic variable: the phase difference of a josephson junction". Science. 239 (4843): 992–997. doi:10.1126/science.239.4843.992. ISSN   0036-8075. PMID   17815701. S2CID   1732678.
  6. ↑ Welty, Richard P.; Martinis, John M. (March 1993). "Two-stage integrated SQUID amplifier with series array output". IEEE Transactions on Applied Superconductivity. 3: 2605–2608. doi:10.1109/77.233523. ISSN   1051-8223. S2CID   33500389.
  7. ↑ Irwin, K. D.; Hilton, G. C.; Wollman, D. A.; Martinis, John M. (1998-08-05). "X‐ray detection using a superconducting transition‐edge sensor microcalorimeter with electrothermal feedback". Applied Physics Letters. 69 (13): 1945. doi:10.1063/1.117630. ISSN   0003-6951.
  8. ↑ Frederic Lardinois (2014-09-02). "Google Partners With UCSB To Build Quantum Processors For Artificial Intelligence". techcrunch.com. Retrieved 2025-01-18.
  9. 1 2 "Google's Top Quantum Scientist Explains In Detail Why He Resigned". forbes.com. 2020-04-30. Retrieved 2025-01-18.
  10. ↑ Arute, Frank; Arya, Kunal; Babbush, Ryan; Bacon, Dave; Bardin, Joseph C.; Barends, Rami; Biswas, Rupak; Boixo, Sergio; Brandao, Fernando G. S. L.; Buell, David A.; Burkett, Brian (October 2019). "Quantum supremacy using a programmable superconducting processor". Nature. 574 (7779): 505–510. arXiv: 1910.11333 . doi: 10.1038/s41586-019-1666-5 . ISSN   1476-4687. PMID   31645734.
  11. ↑ "Shtetl-Optimized » Blog Archive » Quantum supremacy: the gloves are off". 23 October 2019. Retrieved 2019-11-04.
  12. ↑ "Google's Head of Quantum Computing Hardware Resigns". Wired. ISSN   1059-1028 . Retrieved 2020-04-21.
  13. ↑ "Ex-Google quantum chief joins Simmons' silicon startup". InnovationAus. 2020-09-29. Retrieved 2020-09-29.
  14. ↑ "About us". qolab.ai. Retrieved 2025-01-18.
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