Irfan Siddiqi Abstract

Irfan Siddiqi UC Berkeley

"Quantum Noise in Josephson's 'Frictionless' Pendulum"

The Josephson junction is a unique electrical oscillator which is both non-dissipative and non-linear at tempertures well below the superconducting transition temperature Tc. The equations which describe the dynamics of the junction have the same form as that of a driven physical pendulum. I will show how this anharmonicity enables the realization of sensitive digital and analog amplifiers operating at the quantum limit of sensitivity. Moreover, vanishing internal dissipation reduces backaction and makes such amplifiers particularly well suited to quantum measurements.