학술논문
Super quantum discord for X-type states.
Document Type
Journal
Author
Li, Tao (PRC-CAP-SM) AMS Author Profile; Ma, Teng (PRC-CAP-SM) AMS Author Profile; Wang, Yaokun (PRC-CAP-SM) AMS Author Profile; Fei, Shaoming (PRC-CAP-SM) AMS Author Profile; Wang, Zhixi (PRC-CAP-SM) AMS Author Profile
Source
Subject
81 Quantum theory -- 81P Axiomatics, foundations, philosophy
81P40Quantum coherence, entanglement, quantum correlations
81P40
Language
English
Abstract
Summary: ``Weak measurement is a new way to manipulate and control quantum systems. Different from projection measurement, weak measurement only makes a small change in status. Applying weak measurement to quantum discord, Singh and Pati proposed a new kind of quantum correlations called `super quantum discord (SQD)' [Ann. Phys. {\bf 343},141(2014)] [MR3176162]. Unfortunately, the super quantum discord is also difficult to calculate. There are only few explicit formulae about SQD. We derive an analytical formula of SQD for general X-type two-qubit states, which surpass the conclusion for Werner states and Bell diagonal states. Furthermore, our results reveal more knowledge about the new insight of quantum correlation and give a new way to compare SQD with normal quantum discord. Finally, we analyze its dynamics under nondissipative channels.''