Eur. Phys. J. D (2012) 66: 300
https://doi.org/10.1140/epjd/e2012-30324-9

Regular Article

Franck-Condon effect in central spin system

¹ State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Science, Beijing 100190, P.R. China
² Beijing Computational Science Research Center, Beijing 100084, P.R. China

^a e-mail: yanglp09@itp.ac.cn

Received: 23 May 2012
Received in final form: 8 July 2012
Published online: 4 December 2012

Abstract

We study the quantum transitions of a central spin surrounded by a collective-spin environment. It is found that the influence of the environmental spins on the absorption spectrum of the central spin can be explained with the analog of the Franck-Condon (FC) effect in conventional electron-phonon interaction system. Here, the collective spins of the environment behave as the vibrational mode, which makes the electron transitioned mainly with the so-called “vertical transitions” in the conventional FC effect. The “vertical transition” for the central spin in the spin environment manifests as, the certain collective spin states of the environment is favored, which corresponds to the minimal change in the average of the total spin angular momentum.