Faoro, Lara and Ioffe, Lev and Kitaev, Alexei (2012) Dissipationless dynamics of randomly coupled spins at high temperatures. Physical Review B, 86 (13). Art. No. 134414. ISSN 1098-0121. http://resolver.caltech.edu/CaltechAUTHORS:20120713-092458311
- Published Version
See Usage Policy.
- Submitted Version
See Usage Policy.
Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:20120713-092458311
We develop a technique to compute the high-frequency asymptotics of spin correlators in weakly interacting disordered spin systems. We show that the dynamical spin correlator decreases exponentially at high frequencies ⟨SS⟩_ω ∼ exp(−τ∗ω) and compute the characteristic time τ∗ of this dependence. In a typical random configuration, some fraction of spins form strongly coupled pairs, which behave as two-level systems. Their switching dynamics is driven by the high-frequency noise from the surrounding spins, resulting in low-frequency 1/f noise in the magnetic susceptibility and other physical quantities. We discuss application of these results to the problem of susceptibility and flux noise in superconducting circuits at mK temperatures.
|Additional Information:||© 2012 American Physical Society. Received 1 February 2012; published 15 October 2012. We are grateful to R. McDermott for the discussion of the experimental situation. This work was supported, in part, by Triangle de la physique 2007-36, ANR-06-BLAN-0218, ECS-0608842, ARO W911-09-1-0395, DARPA HR0011-09-1-0009. A.K. acknowledges funding by the Institute of Quantum Information under NSF Grant No. PHY-0803371.|
|Group:||IQIM, Institute for Quantum Information and Matter|
|Classification Code:||PACS number(s): 42.50.Lc|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Tony Diaz|
|Deposited On:||19 Jul 2012 22:23|
|Last Modified:||09 Jan 2016 01:53|
Repository Staff Only: item control page