Purified discord and multipartite entanglement |
| |
| Authors: | Eric G Brown Eric J Webster Eduardo Martín-Martínez Achim Kempf |
| |
| Institution: | 1. Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada;2. Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada;3. Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada;4. Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5, Canada;5. Centre for Quantum Computing Technology, Department of Physics, University of Queensland, St. Lucia, Queensland 4072, Australia |
| |
| Abstract: | We study bipartite quantum discord as a manifestation of a multipartite entanglement structure in the tripartite purified system. In particular, we find that bipartite quantum discord requires the presence of both bipartite and tripartite entanglement in the purification. This allows one to understand the asymmetry of quantum discord, D(A,B)≠D(B,A) in terms of entanglement monogamy. As instructive special cases, we study discord for qubits and Gaussian states in detail. As a result of this we shed new light on a counterintuitive property of Gaussian states: the presence of classical correlations necessarily requires the presence of quantum correlations. Finally, our results also shed new light on a protocol for remote activation of entanglement by a third party. |
| |
| Keywords: | Quantum discord Multipartite entanglement Remote quantum resource activation |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
