Eur. Phys. J. B 36, 263-269 (2003)
https://doi.org/10.1140/epjb/e2003-00343-8

Landau-Zener interferometry for qubits

¹ L.D. Landau Institute for Theoretical Physics, Moscow 117940, Russia
² Institute for Theoretical Physics, University of California at Santa Barbara, USA
³ Institute for Theoretical Physics, ETH-Zürich, 8093, Switzerland

Corresponding author: ^a shytov@cmt.harvard.edu

Received: 22 July 2003
Revised: 21 October 2003
Published online: 8 December 2003

Abstract

One may probe coherence of a qubit by periodically sweeping its control parameter. The qubit is then excited by the Landau-Zener (LZ) mechanism. The interference between multiple LZ transitions leads to an oscillatory dependence of the energy absorption rate on the sweeping amplitude and on the period. This interference pattern allows to determine the decoherence time of the qubit. We introduce a simple phenomenological model describing this “interferometer”, and find the form of the interference pattern.