Photon-assisted Landau-Zener transition: Role of coherent superposition states

Zhe Sun, Jian Ma, Xiaoguang Wang, and Franco Nori

Phys. Rev. A 86, 012107 – Published 16 July 2012

Abstract

We investigate a Landau-Zener (LZ) transition process modeled by a quantum two-level system (TLS) coupled to a photon mode when the bias energy is varied linearly in time. The initial state of the photon field is assumed to be a superposition of coherent states, leading to a more intricate LZ transition. Applying the rotating-wave approximation (RWA), analytical results are obtained revealing the enhancement of the LZ probability by increasing the average photon number. We also consider the creation of entanglement and the change of photon statistics during the LZ process. Without the RWA, we find some qualitative differences of the LZ dynamics from the RWA results; e.g., the average photon number no longer monotonically enhances the LZ probability. The ramifications and implications of these results are explored.

Received 3 May 2012

DOI:https://doi.org/10.1103/PhysRevA.86.012107

Authors & Affiliations

Zhe Sun^1,2,*, Jian Ma^1,3, Xiaoguang Wang^1,3, and Franco Nori^1,4

¹Advanced Science Institute, RIKEN, Wako-shi, Saitama 351-0198, Japan
²Department of Physics, Hangzhou Normal University, Hangzhou 310036, China
³Zhejiang Institute of Modern Physics, Department of Physics, Zhejiang University, Hangzhou 310027, China
⁴Physics Department, The University of Michigan, Ann Arbor, Michigan 48109-1040, USA

^*sunzhe@hznu.edu.cn

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand

Issue

Vol. 86, Iss. 1 — July 2012

Reuse & Permissions

Access Options

Author publication services for translation and copyediting assistance advertisement

Physical Review A

covering atomic, molecular, and optical physics and quantum information