Entanglement in bipartite pure states of an interacting boson gas obtained by local projective measurements
- C. N. Yang Institute for Theoretical Physics, State University of New York at Stony Brook, New York 11794-3840 (United States)
- Department of Systems Engineering and Automation, Technical University of Cartagena, ES-30202 Cartagena (Spain)
- Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom)
We quantify the extractable entanglement of excited states of a Lieb-Liniger gas that are obtained from coarse-grained measurements on the ground state in which the boson number in one of two complementary contiguous partitions of the gas is determined. Numerically exact results obtained from the coordinate Bethe ansatz show that the von Neumann entropy of the resulting bipartite pure state increases monotonically with the strength of repulsive interactions and saturates to the impenetrable-boson limiting value. We also present evidence indicating that the largest amount of entanglement can be extracted from the most probable projected state having half the number of bosons in a given partition. Our study points to a fundamental difference between the nature of the entanglement in free-bosonic and free-fermionic systems, with the entanglement in the former being zero after projection, while that in the latter (corresponding to the impenetrable-boson limit) being nonzero.
- OSTI ID:
- 22068675
- Journal Information:
- Physical Review. A, Vol. 84, Issue 3; Other Information: (c) 2011 American Institute of Physics; Country of input: Syrian Arab Republic; ISSN 1050-2947
- Country of Publication:
- United States
- Language:
- English
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