Schumm Group
TU Wien   Quantum-enhanced measurement and metrology
Quantum-enhanced measurement and metrology - Schumm Group
Quantum-enhanced measurement and metrology – Schumm Group

Quantum noise thermometry for bosonic Josephson junctions in the mean-field regime

Author(s): A. Gottlieb, Thorsten Schumm

Journal: Phys. Rev. A

Volume: 79

Page(s): 063601

Year: 2009

DOI Number: 10.1103/PhysRevA.79.063601

Link: Link to publication


Bosonic Josephson junctions can be realized by confining ultracold gases of bosons in multiwell traps and studied theoretically with the M-site Bose-Hubbard model. We show that canonical equilibrium states of the M-site Bose-Hubbard model may be approximated by mixtures of coherent states, provided the number of atoms is large and the total energy is comparable to kBT. Using this approximation, we study thermal fluctuations in bosonic Josephson junctions in the mean-field regime. Statistical estimates of the fluctuations of relative phase and number, obtained by averaging over many replicates of an experiment, can be used to estimate the temperature and the tunneling parameter or to test whether the experimental procedure is effectively sampling from a canonical thermal equilibrium ensemble.


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