Tricritical point in the quantum Hamiltonian mean-field model
arXiv:2202.08855 · doi:10.1103/PhysRevE.106.024109
Abstract
Engineering long-range interactions in experimental platforms has been achieved with great success in a large variety of quantum systems in recent years. Inspired by this progress, we propose a generalization of the classical Hamiltonian mean-field model to fermionic particles. We study the phase diagram and thermodynamic properties of the model in the canonical ensemble for ferromagnetic interactions as a function of temperature and hopping. At zero temperature, small charge fluctuations drive the many-body system through a first order quantum phase transition from an ordered to a disordered phase at zero temperature. At higher temperatures, the fluctuation-induced phase transition remains first order initially and switches to second order only at a tricritical point. Our results offer an intriguing example of tricriticality in a quantum system with long-range couplings, which bears direct experimental relevance. The analysis is performed by exact diagonalization and mean-field theory.
References in corpus (6)
- Statistical mechanics and dynamics of solvable models with long-range interactions
- Cold atoms in cavity-generated dynamical optical potentials
- Roton-type mode softening in a quantum gas with cavity-mediated long-range interactions
- Prethermalization of atoms due to photon-mediated long-range interactions
- An SYK-inspired model with density-density interactions: spectral & wave function statistics, Green's function and phase diagram
- First numerical evidence of Janssen-Oerding's prediction in a three-dimensional spin model far from equilibrium