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arXiv · 1705.05968

Suppression of the Landau-Zener transition probability by a weak classical noise

Rajesh K. Malla·E. G. Mishchenko·M. E. Raikh
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Abstract

When the drive which causes the level crossing in a qubit is slow, the probability, P_{LZ}, of the Landau-Zener transition is close to 1. We show that in this regime, which is most promising for applications, the noise due to the coupling to the environment, reduces the average P_{LZ}. At the same time, the survival probability, 1-P_{LZ}, which is exponentially small for a slow drive, can be completely dominated by noise-induced correction. Our main message is that the effect of a weak classical noise can be captured analytically by treating it as a perturbation in the Schroedinger equation. This allows us to study the dependence of the noise-induced correction to P_{LZ} on the correlation time of the noise. As this correlation time exceeds the bare Landau-Zener transition time, the effect of noise becomes negligible. We consider two conventional realizations of noise: Gaussian noise and telegraph noise.

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Rajesh K. Malla, E. G. Mishchenko, M. E. Raikh. 2017-05-17. Suppression of the Landau-Zener transition probability by a weak classical noise. https://doi.org/10.1103/physrevb.96.075419

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