Quantum phase transitions of atom-molecule Bose mixtures in a double-well potential

Abstract

The ground state and spectral properties of Bose gases in double-well potentials are studied in two different scenarios: i) an interacting atomic Bose gas, and ii) a mixture of an atomic gas interacting with diatomic molecules. A ground state second-order quantum phase transition (QPT) is observed in both scenarios. For large attractive values of the atom-atom interaction, the ground-state is degenerate. For repulsive and small attractive interaction, the ground-state is not degenerate and is well approximated by a boson coherent state. Both systems depict an excited state quantum phase transition (ESQPT). For the mixed atom-molecule system the critical point of the ESQPT displays a discontinuity in the first derivative of the density of states.

25 pages, 18 figures. RevTex 4.1 (version to appear in Phys. Rev. E)

References in corpus (4)

• Excited state quantum phase transitions in many-body systems
• Exact spectrum of the Lipkin-Meshkov-Glick model in the thermodynamic limit and finite-size corrections
• Quantum Dynamics and Statistics Properties of Atom-Molecule Bose-Einstein Condensate
• Quantum switching at a mean-field instability of a Bose-Einstein condensate in an optical lattice

Cited by in corpus (9)

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• Excited-state quantum phase transition in the Rabi model
• Dynamical and excited-state quantum phase transitions in collective systems
• Excited-state quantum phase transitions in systems with two degrees of freedom: III. Interacting boson systems
• Theory of dynamical phase transitions in quantum systems with symmetry-breaking eigenstates
• Mechanism of dynamical phase transitions: The complex-time survival amplitude
• Constants of motion characterizing continuous symmetry-broken phases
• Excited-state quantum phase transitions in constrained systems
• Energy cat states induced by a parity-breaking excited-state quantum phase transition