Prof. Nadav Katz - Quantum Superconducting Circuitry - Defects, Amplification and Sensing
Date: Monday, June 1 2020, at 14:00pm (Israel time)
Abstract:
Recent experiments on superconducting quantum circuits have revealed an exciting (and detrimental) source of noise – two-level-defects in native oxides on surfaces and interfaces. I will show our recent spectroscopic probing of these defects with a novel two-tone spectroscopy of coupled devices, with the aim of a deeper understanding of the subtleties of this highly non-trivial noise bath.
High kinetic inductance materials are an interesting addition to the arsenal of coherent superconducting devices. They are based on inductive reactance of the material due to kinetic energy of the charge carriers. This is usually neglected in standard conductors at frequencies below THz. However, in specific superconductors this effect can overwhelm the conventional magnetic inductance by orders of magnitude. I will show HUJI's implementation of such devices (resonators and travelling wave amplifiers) based on amorphous Tungsten Silicide films grown by sputtering. I will discuss wave mixing phenomena (including quantum effects) in these devices, both 4wave and 3wave. Going beyond, I will show how a new regime of itinerant quantum optics can be carried out in such a system.
