Nonlinear Landau-Zener tunneling in Majorana's stellar representation

作者:Guo, Qiuyi*; Liu, Haodi; Zhou, Tianji; Chen, Xu-Zong; Wu, Biao
来源:European Physical Journal D, 2016, 70(6): 128.
DOI:10.1140/epjd/e2016-70059-y

摘要

By representing the evolution of a quantum state with the trajectories of the stars on a Bloch sphere, the Majorana's stellar representation provides an intuitive way to understand quantum motion in a high dimensional projective Hilbert space. In this work we show that the Majorana's representation offers a very interesting and intuitive way to understand the nonlinear Landau-Zener tunneling. In particular, the breakdown of adiabaticity in this tunneling phenomenon can be understood as some of the stars never reaching the south pole. We also establish a connection between the Majorana stars in the second quantized model and the single star in the mean field model by using the reduced density matrix.