Temperature-driven BCS-BEC crossover in a coupled boson-fermion system
arXiv:1706.04197 · doi:10.1103/PhysRevB.102.144506
Abstract
We propose a simple bose-fermi model in two dimensions, with a coupling that converts pairs of opposite spin fermions into localized bosons and vice versa. We show that tracing out one of the degrees, either the bosons or fermions, generates temperature-dependent long range effective interactions between bosons as well as effective attractive interactions between fermions. Using Monte Carlo techniques we obtain the thermodynamic properties and phase stiffness as a function of temperature, dominated by vortex-antivortex unbinding of the bosons. Remarkably in the fermion sector we observe a temperature-induced BCS-BEC crossover signaled by a distinct change of their spectral properties: the minimum gap locus moves from the Fermi wave vector to the point. Such a model is relevant for describing aspects of high superconductivity in cuprates and pnictides, superconducting islands on graphene, and bose-fermi mixtures in cold atomic systems.
10 pages, 10 figures
References in corpus (10)
- Theory of Intertwined Orders in High Temperature Superconductors
- Phase diagram of a two-component Fermi gas with resonant interactions
- Self-organized topological state in the magnetic chain on the surface of a superconductor
- Superconductor-Insulator Transition and Fermi-Bose Crossovers
- Parallelized Traveling Cluster Approximation to Study Numerically Spin-Fermion Models on Large Lattices
- Charge Dynamics Across the Disorder Driven Superconductor-Insulator Transition
- Topological superconductivity at finite temperatures in proximitized magnetic nanowires
- From an insulating to a superfluid pair-bond liquid
- Critical conductance of the chiral 2d random flux model
- Josephson coupling between superconducting islands on single and bilayer graphene