Dissipative Landau-Zener transition with decoherence rate

TL;DR

This paper introduces a simple microscopic model for the dissipative Landau-Zener transition that captures the effects of decoherence and reveals a non-monotonic flipping probability, offering new insights and practical measurement methods.

Contribution

The work presents a minimal parameter model that unifies known formulas and describes non-monotonic transition probabilities due to decoherence effects.

Findings

Derived equations recover Landau-Zener and Kayanuma formulas in limiting cases.

Identified non-monotonic flipping probability as a function of sweeping velocity.

Proposed an alternative method for measuring decoherence rates in quantum systems.

Abstract

An innovative microscopic model with a minimal number of parameters: tunneling splitting gap, external field sweeping velocity, and decoherence rate is used to describe dynamics of the dissipative Landau-Zener transition in the presence of the decoherence. In limiting cases, the derived equation of motion gives rise to the well-known Landau-Zener and Kayanuma formula. In a general case, the description demonstrates a non-monotonic flipping probability with respect to the sweeping velocity, which is also found in some other models. This non-monotony can be explained by considering the competition and timescale of the quantum tunneling, crossing period, and decoherence process. The simplicity and robustness of the theory offer a practical and novel description of the Landau-Zener transition. In addition, it promises an alternative method to the electron paramagnetic resonance in measuring the effective decoherence rate of relevant quantum systems.