| Maximizing Thermal Entanglement of XY Model Using Site-Dependent Magnetic Fields in Specific Directions |
| |
| 作者姓名： | 陈文岭 杨东 顾世建 |
| |
| 作者单位： | [1]Department of Physics and ITP, The Chinese University of Hong Kong, Hong Kong [2]Laboratory for Quantum Information and Department of Physics, China Jiliang University, Hangzhou 310018 |
| |
| 基金项目： | Supported by the Earmarked Grant for Research from the Research Grants Council of HKSAR of China under Grant No CUHK N_CUHK204/05. |
| |
| 摘 要： | We study the thermal entanglement by means of concurrence in a two-qubit isotropic XY model in the presence of site-dependent external magnetic fields in arbitrary directions. We find that at a given temperature and magnetic field strength, the mirror symmetry of the two fields about the x-y plane is a necessary condition for maximum entanglement. However, if there is no constraint on the field strengths, then the necessary condition for maximum entanglement reduces to the configuration that the two fields are vertical, anti-parallel and with the same strength. We also investigate the anisotropic XY model and find that the above conclusion more or less holds.
|
| 关 键 词： | 极值 热缠结 磁场 量子信息 |
| 收稿时间： | 2007-12-06 |
Maximizing Thermal Entanglement of XY Model Using Site-Dependent Magnetic Fields in Specific Directions |
| |
| CHAN Wen-Ling,YANG Dong,GU Shi-Jian.Maximizing Thermal Entanglement of XY Model Using Site-Dependent Magnetic Fields in Specific Directions[J].Chinese Physics Letters,2008,25(3):832-835. |
| |
| Authors: | CHAN Wen-Ling YANG Dong GU Shi-Jian |
| |
| Affiliation: | Department of Physics and ITP, The Chinese University of Hong Kong, Hong KongLaboratory for Quantum Information and Department of Physics, China Jiliang University, Hangzhou 310018 |
| |
| Abstract: | We study the thermal entanglement by means of concurrence in a two-qubit isotropic XY model in the presence of site-dependent external magnetic fields in arbitrary directions. We find that at a given temperature and magnetic field strength, the mirror symmetry of the two fields about the x-y plane is a necessary condition for maximum entanglement. However, if there is no constraint on the field strengths, then the necessary condition for maximum entanglement reduces to the configuration that the two fields are vertical, anti-parallel and with the same strength. We also investigate the anisotropic XY model and find that the above conclusion more or less holds. |
| |
| Keywords: | 03 67 Lx 03 67 Mn 75 10 Jm |
| 本文献已被 维普 等数据库收录！ |
| 点击此处可从《中国物理快报》浏览原始摘要信息 |
|
点击此处可从《中国物理快报》下载免费的PDF全文 |
