Share Email Print

Proceedings Paper

Stationary and non-stationary noise in superconducting quantum devices
Author(s): I. Martin; L. Bulaevskii; A. Shnirman; Y. M. Galperin
Format Member Price Non-Member Price
PDF $17.00 $21.00

Paper Abstract

We consider two representative problems that deal with the fluctuator-induced decoherence from two very different perspectives-microscopic and macroscopic. In the first part, we consider an individual two-level system inside a Josephson junction shunted by a resistor. If the TLS modulates the Josephson energy and/or is optically active, it can be Rabi driven by the Josephson oscillation. The Rabi oscillations, in turn, translate into oscillations of current and voltage which can be detected in noise measurements. This effect provides an option to fully characterize the TLS inside Josephson junction and to find the TLS's contribution to the decoherence when the junction is used as a qubit. In the second part, we study the contribution of an ensemble of non-stationary glassy charge fluctuators on qubit decoherence. Low-temperature dynamics of insulating glasses is dominated by a macroscopic concentration of tunneling two-level systems. Due to exponentially broad distribution of their tunneling rates and the finite experimental manipulation timescales, some of the fluctuators are temporarily stuck in high-energy non-thermal states. We find that at low enough temperatures, non-stationary contribution due to these slow non-thermal fluctuators can dominate the stationary (thermal) one, and discuss how this effect can be minimized.

Paper Details

Date Published: 8 June 2007
PDF: 12 pages
Proc. SPIE 6600, Noise and Fluctuations in Circuits, Devices, and Materials, 660005 (8 June 2007); doi: 10.1117/12.725639
Show Author Affiliations
I. Martin, Los Alamos National Lab. (United States)
L. Bulaevskii, Los Alamos National Lab. (United States)
A. Shnirman, Univ. Karlsruhe (Germany)
Y. M. Galperin, Univ. of Oslo (Norway)
Argonne National Lab. (United States)
A.F. Ioffe Physico-Technical Institute (Russia)

Published in SPIE Proceedings Vol. 6600:
Noise and Fluctuations in Circuits, Devices, and Materials
Massimo Macucci; Lode K.J. Vandamme; Carmine Ciofi; Michael B. Weissman, Editor(s)

© SPIE. Terms of Use
Back to Top