Speaker
Prof.
Leonid Glazman
(Yale University, USA)
Description
Abstract: Recent development of a new type of a qubit,
fluxonium, facilitated the observation of two elusive
quantum effects. The first of the two is the interference
between separated in space quantum phase slips. The
second one is the produced by quasiparticles dissipative
component of the Josephson current. The interference of
phase slips manifested itself via inhomogeneous broadening
of the qubit oscillations frequency. The dissipative effect of
quasiparticles was quantified by measuring the T1 time of
the qubit. This latter measurement actually resolved the so-
called "cosine-phi" problem which existed since the time the
Josephson effect has been predicted. This talk covers the
theory of the fluxonium qubit, and its use in designing the
experiments and interpreting the data.