Localization of Metal-Induced Gap States at the Metal-Insulator Interface: Origin of Flux Noise in SQUIDs and Superconducting Qubits

SangKook Choi, Dung-Hai Lee, Steven G. Louie, and John Clarke
Phys. Rev. Lett. 103, 197001 – Published 3 November 2009
PDFHTMLExport Citation

Abstract

The origin of magnetic flux noise in superconducting quantum interference devices with a power spectrum scaling as 1/f (f is frequency) has been a puzzle for over 20 years. This noise limits the decoherence time of superconducting qubits. A consensus has emerged that the noise arises from fluctuating spins of localized electrons with an areal density of 5×1017m2. We show that, in the presence of potential disorder at the metal-insulator interface, some of the metal-induced gap states become localized and produce local moments. A modest level of disorder yields the observed areal density.

  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Received 21 July 2009

DOI:https://doi.org/10.1103/PhysRevLett.103.197001

©2009 American Physical Society

Authors & Affiliations

SangKook Choi, Dung-Hai Lee, Steven G. Louie, and John Clarke*

  • Department of Physics, University of California, Berkeley, California 94720, USA
  • Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA

  • *jclarke@berkeley.edu

Article Text (Subscription Required)

Click to Expand

Supplemental Material (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 103, Iss. 19 — 6 November 2009

Reuse & Permissions
Access Options
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review Letters

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×