Quantum Information Approach to Bose-Einstein Condensate in a Tilted Double-Well System

Abstract

We study the ground state properties of bosons in a tilted double-well system. We use fidelity susceptibility to identify the possible ground state transitions under different tilt values. For a very small tilt (for example $10^{-10}$), two transitions are found. For a moderate tilt (for example $10^{-3}$), only one transition is found. For a large tilt (for example $10^{-1}$), no transition is found. We explain this by analyzing the spectrum of the ground state. The quantum discord and total correlation of the ground state under different tilts are also calculated to indicate those transitions. In the transition region, both quantities have peaks decaying exponentially with particle number $N$. This means for a finite-size system the transition region cannot be explained by the mean-field theory, but in the large-$N$ limit it can be.

5 pages, 5 figures, slightly different from the published version

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Cited by in corpus (2)

• The classical-quantum boundary for correlations: discord and related measures
• Critical exponents for an impurity in a bosonic Josephson junction: Position measurement as a phase transition