Regular Article

Robustness of qubit–qudit entanglement under decoherence

College of Physics, Jilin University, Changchun 130012, P.R. China

^a e-mail: suxm@jlu.edu.cn

Received: 24 October 2018
Received in final form: 15 January 2019
Published online: 19 March 2019

Abstract

We investigate the robustness of entanglement for a qubit-qudit system under depolarizing and dephasing channels. For depolarizing channel, we obtain a simple analytical expression of entanglement evolution. It is shown that the larger dimension d a qudit subsystem has, the more robust a pure state becomes. For dephasing channel, we find the most robust entangled states and the most fragile ones. Moreover, the robustness of these states is independent of the qudit’s dimension d.