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Incoming links: Superconducting device
John M. Martinis Created 2026-10-18 Updated 2026-11-05
John M. Martinis coauthored a 1985 observation of quantized energy levels in a current-biased Josephson junction. The relevant coordinate was the phase difference across an electrical circuit element, rather than the position of one isolated particle. The measured levels agreed with a quantum mechanics calculation using junction parameters measured in the classical regime. This showed that a fabricated superconducting circuit could possess a discrete excitation spectrum suitable for controlled quantum experiments.[ref]
A physicist researching superconducting devices and quantum computers based on Josephson junctions.[ref]
John Martinis by University of California, Santa Barbara. Distinguished Professor; research paragraph on superconducting devices and Josephson-junction quantum bits
Portrait of John M. Martinis
. David Orban, Flickr photograph, 13 February 2007; existing Commons crop. Creative Commons Attribution 2.0 Generic., via Wikimedia Commons. Source.
Superconducting device Created 2026-10-18 Updated 2026-11-05
A superconducting device uses superconducting behavior to perform a function such as generating a strong magnetic field, detecting flux, switching or manipulating quantum states. Examples include superconducting magnets, SQUIDs and Josephson junction circuits.
Its performance depends on the full operating environment: temperature, magnetic field, applied current, losses and thermal coupling. A superconducting component does not make every part of a device lossless. Junction interfaces, quasiparticles and vortices can produce measurable dissipation or noise even when the intended circuit element has a superconducting state.