On Tuesday, January 10, a symposium in honor of John Clarke was held on the UC Berkeley campus. Talks were presented by many scientists whose work has been influenced by John Clarke, a world-renowned scientist.
For almost 50 years, John Clarke has been a guiding light in harnessing features of quantum mechanics for practical use. He is the world’s leading authority on the design, understanding, and application of SQUIDs (Superconducting Quantum Interference Devices). SQUIDS are exquisitely sensitive magnetometers that serve as central components in a wide range of important technologies and scientific endeavors, from nuclear magnetic resonance imaging to searching for cold dark matter to investigating fundamental quantum properties.
A member of the Berkeley Physics faculty since 1969, John is now Professor of the Graduate School. He is a Fellow of the Royal Society, from which he received the Hughes Medal, and a Foreign Associate of the National Academy of Sciences, from which he received the Comstock Prize in Physics.
One of Clarke’s hallmark contributions, accomplished with postdoc Michel Devoret and graduate student John Martins, was the first demonstration of quantized energy in a mesoscopic system. Their experiment demonstrated that the energy of a single Josephson junction is quantized, just as for atoms. In John’s words: “They showed that their junction really did behave as a quantum mechanical object.”
John’s recent research conducted with Will Oliver and others at MIT and MIT-Lincoln Laboratory studied a modified version of the superconducting flux qubit. One of his current interests is trying to gain a better understanding of the fundamental physical processes that lead to relaxation and decoherence in superconducting qubits.