Protecting quantum coherence and discord from decoherence of depolarizing noise via weak measurement and measurement reversal

¹ School of Physics, Huazhong University of Science and Technology - Wuhan 430074, China
² Quantum Optics Lab., Department of Physics, COMSATS Institute of Information Technology - Islamabad, Pakistan

Received: 17 March 2017
Accepted: 14 June 2017

Abstract

Protection of the quantum coherence and discord in realistic quantum systems interacting with the environment of depolarizing noise is an important subject in quantum information processing. Weak measurement and measurement reversal can effectively suppress the amplitude damping-class decoherence. In this paper, we examine the effect of this protocol in the protection of quantum coherence and discord subjected to depolarizing noise environments. Our scheme consists of a prior weak measurement on each qubit before interacting with noisy channels followed by post measurement reversal. It is found that quantum coherence and discord can be enhanced to an optimal value by performing weak measurements and adjusting measurement parameters on each qubit. In addition, the maximal value of the quantum coherence and discord is found to be independent of the initial-state parameters.