### 摘要

We consider the entanglement dynamics between two Unruh-DeWitt detectors at rest separated at a distance d. This simple model when analyzed properly in quantum field theory shows many interesting facets and helps to dispel some misunderstandings of entanglement dynamics. We find that there is spatial dependence of quantum entanglement in the stable regime due to the phase difference of vacuum fluctuations the two detectors experience, together with the interference of the mutual influences from the backreaction of one detector on the other. When two initially entangled detectors are still outside each other's light cone, the entanglement oscillates in time with an amplitude dependent on spatial separation d. When the two detectors begin to have causal contact, an interference pattern of the relative degree of entanglement (compared to those at spatial infinity) develops a parametric dependence on d. The detectors separated at those d with a stronger relative degree of entanglement enjoy longer disentanglement times. In the cases with weak coupling and large separation, the detectors always disentangle at late times. For sufficiently small d, the two detectors can have residual entanglement even if they initially were in a separable state, while for d a little larger, there could be transient entanglement created by mutual influences. However, we see no evidence of entanglement creation outside the light cone for initially separable states.

原文 | English |
---|---|

文章編號 | 085020 |

期刊 | Physical Review D - Particles, Fields, Gravitation and Cosmology |

卷 | 79 |

發行號 | 8 |

DOIs | |

出版狀態 | Published - 2009 四月 1 |

### 指紋

### All Science Journal Classification (ASJC) codes

- Nuclear and High Energy Physics
- Physics and Astronomy (miscellaneous)

### 引用此文

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**Temporal and spatial dependence of quantum entanglement from a field theory perspective.** / Lin, Shih Yuin; Hu, B. L.

研究成果: Article

TY - JOUR

T1 - Temporal and spatial dependence of quantum entanglement from a field theory perspective

AU - Lin, Shih Yuin

AU - Hu, B. L.

PY - 2009/4/1

Y1 - 2009/4/1

N2 - We consider the entanglement dynamics between two Unruh-DeWitt detectors at rest separated at a distance d. This simple model when analyzed properly in quantum field theory shows many interesting facets and helps to dispel some misunderstandings of entanglement dynamics. We find that there is spatial dependence of quantum entanglement in the stable regime due to the phase difference of vacuum fluctuations the two detectors experience, together with the interference of the mutual influences from the backreaction of one detector on the other. When two initially entangled detectors are still outside each other's light cone, the entanglement oscillates in time with an amplitude dependent on spatial separation d. When the two detectors begin to have causal contact, an interference pattern of the relative degree of entanglement (compared to those at spatial infinity) develops a parametric dependence on d. The detectors separated at those d with a stronger relative degree of entanglement enjoy longer disentanglement times. In the cases with weak coupling and large separation, the detectors always disentangle at late times. For sufficiently small d, the two detectors can have residual entanglement even if they initially were in a separable state, while for d a little larger, there could be transient entanglement created by mutual influences. However, we see no evidence of entanglement creation outside the light cone for initially separable states.

AB - We consider the entanglement dynamics between two Unruh-DeWitt detectors at rest separated at a distance d. This simple model when analyzed properly in quantum field theory shows many interesting facets and helps to dispel some misunderstandings of entanglement dynamics. We find that there is spatial dependence of quantum entanglement in the stable regime due to the phase difference of vacuum fluctuations the two detectors experience, together with the interference of the mutual influences from the backreaction of one detector on the other. When two initially entangled detectors are still outside each other's light cone, the entanglement oscillates in time with an amplitude dependent on spatial separation d. When the two detectors begin to have causal contact, an interference pattern of the relative degree of entanglement (compared to those at spatial infinity) develops a parametric dependence on d. The detectors separated at those d with a stronger relative degree of entanglement enjoy longer disentanglement times. In the cases with weak coupling and large separation, the detectors always disentangle at late times. For sufficiently small d, the two detectors can have residual entanglement even if they initially were in a separable state, while for d a little larger, there could be transient entanglement created by mutual influences. However, we see no evidence of entanglement creation outside the light cone for initially separable states.

UR - http://www.scopus.com/inward/record.url?scp=66849104307&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=66849104307&partnerID=8YFLogxK

U2 - 10.1103/PhysRevD.79.085020

DO - 10.1103/PhysRevD.79.085020

M3 - Article

AN - SCOPUS:66849104307

VL - 79

JO - Physical Review D - Particles, Fields, Gravitation and Cosmology

JF - Physical Review D - Particles, Fields, Gravitation and Cosmology

SN - 1550-7998

IS - 8

M1 - 085020

ER -