Professor Bei-Lok Hu (University of Maryland)

Quantum Nonlocality in EPR from Field Theory Perspective

Abstract:
We study a simple system of two two-level atoms (qubits) [2] or two harmonic oscillators [3] placed at a spatial separation (including spacelike separation) interacting with a common quantum field. Our results on the temporal and spatial dependence of entanglement is used to understand the meaning of `quantum nonlocality’ often attached (too loosely) to the Einstein-Podolsky-Rosen (EPR) paradox [1]. From quantum field theory we see how the operational interpretation / definition of EPR pertaining to quantum `nonlocality’ is erred, at least misplaced, and ideas like `spooky action’ introduced to explain this phenomenon extraneous. There is entanglement at space-like separation but there is no quantum `nonlocality’ or any sense of causality violation. [1] A. Einstein, B. Podolsky and R. Rosen, Phys. Rev. 47, 777 (1935). [2] C. Anastopoulos, S. Shresta and B. L. Hu, ``Quantum Entanglement under Non-Markovian Dynamics of Two Qubits Interacting with a Common Electromagnetic Field” [quant-ph/0610007] [3] S. Y. Lin and B. L. Hu, “Temporal and Spatial Dependence of Quantum Entanglement: Quantum `Nonlocality' in EPR from Field Theory Perspective”

2009 年 1 月 09 日
14:30~15:30

RM 111, New Physics Building