Interferometric sensitivity and entanglement by scanning through quantum phase transitions in spinor Bose-Einstein condensates

authored by

P. Feldmann, M. Gessner, M. Gabbrielli, C. Klempt, L. Santos, L. Pezzè, A. Smerzi

Abstract

Recent experiments demonstrated the generation of entanglement by quasiadiabatically driving through quantum phase transitions of a ferromagnetic spin-1 Bose-Einstein condensate in the presence of a tunable quadratic Zeeman shift. We analyze, in terms of the Fisher information, the interferometric value of the entanglement accessible by this approach. In addition to the Twin-Fock phase studied experimentally, we unveil a second regime, in the broken axisymmetry phase, which provides Heisenberg scaling of the quantum Fisher information and can be reached on shorter time scales. We identify optimal unitary transformations and an experimentally feasible optimal measurement prescription that maximize the interferometric sensitivity. We further ascertain that the Fisher information is robust with respect to nonadiabaticity and measurement noise. Finally, we show that the quasiadiabatic entanglement preparation schemes admit higher sensitivities than dynamical methods based on fast quenches.

Organisation(s)

Institute of Theoretical Physics
Institute of Quantum Optics
CRC 1227 Designed Quantum States of Matter (DQ-mat)

External Organisation(s)

QSTAR
CNR National Institute of Optics (INO)
European Laboratory for Non-linear Spectroscopy (LENS)
University of Florence (UniFi)

Type

Article

Journal

Physical Review A

Volume

97

ISSN

2469-9926

Publication date

03.2018

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Atomic and Molecular Physics, and Optics

Electronic version(s)

https://doi.org/10.1103/PhysRevA.97.032339 (Access: Closed)
https://doi.org/10.15488/3586 (Access: Open)