John Clarke (physicist)

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John Clarke
FRS
John Clarke (physicist) 2025 (4x5).png
Clarke in 2025
Born (1942-02-10) 10 February 1942 (age 83)
Cambridge, England, UK
Education Perse School
Alma mater
Known for
Awards
Scientific career
Fields Condensed matter physics
Institutions University of California, Berkeley (1969–2010)
Doctoral advisor Brian Pippard
Doctoral students John M. Martinis (1985)

John Clarke (born 10 February 1942) is a British experimental physicist and Professor Emeritus at the University of California, Berkeley. [1] He is known for his various works on measurement devices based on superconductivity. Steven Girvin has called Clarke "the godfather of superconducting electronics". [2]

Contents

In the 1980s, Clarke led a research team, that included John M. Martinis and Michel Devoret. [3] Their discoveries in macroscopic quantum phenomena using the Josephson effect earned them the Nobel Prize in Physics in 2025. [3]

Education and career

John Clarke was born on 10 February 1942 in Cambridge, England. [4] [5] He attended the Perse School, before embarking on a Natural Sciences degree at Christ's College, Cambridge. [6] He graduated with a B.A. in Physics in 1964, and then studied for a Ph.D. in Physics in the Royal Society Mond Laboratory at the University of Cambridge. [7]

In 1965, Clarke became one of the first students to enter the newly founded Darwin College, Cambridge, and was the first president of the Darwin College students' association. [8] While conducting his doctoral work—which was supervised by Brian Pippard—Clarke developed a very sensitive voltmeter, which he later called "SLUG" (Superconducting Low-inductance Undulatory Galvanometer). [6] [7] He obtained his doctorate in 1968. [7] Clarke has said at various times that his work was influenced by Nobel laureate Brian Josephson, who predicted the Josephson effect in 1962 and was also a previous student of Pippard. [9] [10]

After completing his doctorate, Clarke gained a postdoctoral research position at the University of California, Berkeley, and subsequently worked at Berkeley for his whole academic career, as Assistant Professor (1969), Associate Professor (1971), and as Professor of Physics (1973–2010). [11] In 1969, Clarke also joined Lawrence Berkeley National Laboratory, eventually retiring as a faculty senior scientist in the Materials Sciences Division in 2010. [12]

Clarke's association with the University of Cambridge continued, after he moved to the United States. [11] In 1972, he was elected a Fellow of Christ's College; in 1989, he was a visiting fellow at Clare Hall, Cambridge, and in 1998 was elected a by-fellow of Churchill College, Cambridgeand as Professor of Physics (1973–2010). [11] Clarke was awarded a D.Sc. from the University of Cambridge in 2003. [11] He was elected an Honorary Fellow of Christ's College in 1997, and of Darwin College in 2023. [11]

Research

Clarke's research focuses on superconductivity and superconducting electronics, particularly in the development and application of superconducting quantum interference devices (SQUIDs), which are ultrasensitive detectors of magnetic flux. [13] [14] [15]

In 1985, Clarke, John M. Martinis (his Ph.D. student), and Michel Devoret (a postdoctoral researcher at the time) demonstrated the quantum behaviour of a Josephson junction. [3] [16] They showed that at low temperature, a macroscopic electronic state associated with superconductors underwent quantum tunnelling at zero voltage. [17] The same year, by sending microwave pulses of the system, the resonances showed quantised energy levels. [18] This experiment was the first evidence of circuit quantum electrodynamics, that would become later the basis for superconducting quantum computing. [19] [20] The work, which was recognized with the Nobel Prize in Physics in 2025, was largely funded by the Office of Basic Energy Sciences in the United States Department of Energy. [21]

Clarke has also worked in the application of SQUIDs configured as quantum-noise limited amplifiers to search for the axion, a possible component of dark matter. [13]

Awards and honours

Clarke obtained an Alfred P. Sloan fellowship (1970) [22] and a Guggenheim Fellowship (1977). [23] Clarke was elected a Fellow of the Royal Society in 1986. [13] He was awarded the Joseph F. Keithley Award For Advances in Measurement Science in 1998, [24] Comstock Prize in Physics in 1999 [25] , the Hughes Medal [13] and the Olli V. Lounasmaa Memorial Prize in 2004. [26] He was elected a Foreign Associate of the National Academy of Sciences in May 2012. [27] He was elected to the American Philosophical Society in 2017. [28]

In 2021, the Micius Quantum Prize was jointly awarded to Clarke, Michel Devoret and Yasunobu Nakamura. [29]

Clarke, Michel Devoret, and John M. Martinis were jointly awarded the 2025 Nobel Prize in Physics "for the discovery of macroscopic quantum mechanical tunnelling and energy quantisation in an electric circuit". [30]

Works

Selected publications

Books

References

  1. "John Clarke, Professor Emeritus of the Graduate School | Physics". physics.berkeley.edu. Archived from the original on 8 October 2025. Retrieved 7 October 2025.
  2. "Nobel Prize in Physics Is Awarded for Work in Quantum Mechanics". 7 October 2025. Archived from the original on 7 October 2025. Retrieved 9 October 2025.
  3. 1 2 3 "AIP Congratulates 2025 Nobel Prize Winners in Physics - AIP.ORG". AIP. 7 October 2025. Archived from the original on 7 October 2025. Retrieved 7 October 2025.
  4. "John Clarke". nobelprize.org. 7 October 2025. Archived from the original on 7 October 2025. Retrieved 7 October 2025.
  5. "Clarke, John, 1942–". AIP. Retrieved 7 October 2025.
  6. 1 2 "Cambridge Celebrates Its 126th Nobel Laureate as Alumnus John Clarke Wins 2025 Physics Prize". Times Now. 7 October 2025.
  7. 1 2 3 "John Clarke (E) | UC Berkeley Physics". Archived from the original on 7 October 2025.
  8. "John Clarke: DCSA President 1966–67". darwin.cam.ac.uk. July 2024. Retrieved 7 October 2025.
  9. Rogalla, Horst; Kes, Peter H. (11 November 2011). 100 Years of Superconductivity. Taylor & Francis. ISBN   978-1-4398-4948-4.
  10. "Nobel Prize in Physics 2025". NobelPrize.org. Retrieved 9 October 2025.
  11. 1 2 3 4 5 "Professor John Clarke FRS". christs.cam.ac.uk. Retrieved 7 October 2025.
  12. "Former Berkeley Lab Scientist John Clarke Wins 2025 Nobel Prize in Physics". LBL.gov. 24 October 2025.
  13. 1 2 3 4 "John Clarke". Royal Society. 7 October 2025. Archived from the original on 7 October 2025. Retrieved 15 June 2017.
  14. Ford, P. J.; Saunders, G. A. (2005). "9. Electron applications of high temperature super conductors". The Rise of the Superconductors. CRC Press. p. 169. ISBN   978-0-203-64631-1.
  15. Lakhani, Nikhil (2025). Solid-State Physics: Core Principles. Educohack Press. p. 138. ISBN   978-93-6152-073-0.
  16. Hassinger, Sebastian (11 September 2024). The New Quantum Era. "O'Reilly Media, Inc.". ISBN   978-1-0981-4938-3.
  17. "What was the key experiment conducted by Michel H. Devoret, John Clarke, and John M. Martinis at Berkeley? | Britannica". www.britannica.com. 8 October 2025. Retrieved 9 October 2025.
  18. "Quantum effects in electrical circuits honored with Physics Nobel". www.science.org. Retrieved 9 October 2025.
  19. Blais, Alexandre; Grimsmo, Arne L.; Girvin, S. M.; Wallraff, Andreas (19 May 2021). "Circuit quantum electrodynamics". Reviews of Modern Physics. 93 (2) 025005. arXiv: 2005.12667 . Bibcode:2021RvMP...93b5005B. doi:10.1103/RevModPhys.93.025005.
  20. "The ABC of cQED". Nature Physics. 16 (3): 233. 2020. Bibcode:2020NatPh..16..233.. doi:10.1038/s41567-020-0847-3. ISSN   1745-2481.
  21. "The quiet winner of the Nobel Prizes in science". APS.org. 24 October 2025.
  22. "Fellows Database | Alfred P. Sloan Foundation". sloan.org. Retrieved 7 October 2025.
  23. "Guggenheim Fellowships: Supporting Artists, Scholars, & Scientists". www.gf.org. Retrieved 7 October 2025.
  24. "Awards – John Clarke". Berkeleyan. 22 April 1998. Retrieved 7 October 2025.
  25. "Comstock Prize in Physics". National Academy of Sciences. Archived from the original on 29 December 2010. Retrieved 13 February 2011.
  26. "Olli V. Lounasmaa Memorial Prize". Aalto University. Archived from the original on 23 January 2025. Retrieved 7 October 2025.
  27. "National Academy of Sciences Members and Foreign Associates Elected". National Academy of Sciences. 1 May 2012. Archived from the original on 4 May 2012.
  28. "American Philosophical Society: Newly Elected – April 2017". Archived from the original on 15 September 2017. Retrieved 13 June 2017.
  29. "John Clarke Is A Co-Recipient Of The Micius Quantum Prize | Physics". physics.berkeley.edu. Retrieved 7 October 2025.
  30. Nobel Prize (15 September 2025). Announcement of the 2025 Nobel Prize in Physics . Retrieved 7 October 2025 via YouTube.

Further reading