Coexistence of long-range orders in a Bose-Holstein model

Abstract

Exploring supersolidity in naturally occurring and artificially designed systems has been and will continue to be an area of immense interest. Here, we study how superfluid and charge-density-wave (CDW) states cooperate or compete in a minimal model for hard-core-bosons (HCBs) coupled locally to optical phonons: a two-dimensional Bose-Holstein model. Our study is restricted to the parameter regimes of strong HCB-phonon coupling and non-adiabaticity. We use Quantum Monte Carlo simulation (involving stochastic-series-expansion technique) to study phase transitions and to investigate whether we have homogeneous or phase-separated coexistence. The effective Hamiltonian involves, besides a nearest-neighbor hopping and a nearest-neighbor repulsion, sizeable double-hopping terms (obtained from second-order perturbation). At densities not far from half-filling, in the parameter regime where the double-hopping terms are non-negligible (negligible) compared to the nearest-neighbor hopping, we get checkerboard-supersolidity (phase separation) with CDW being characterized by ordering wavevector $\vec{Q}=(\pi ,\pi )$.

arXiv commentRevised version

References in corpus (23)

• Quantum Monte Carlo with Directed Loops
• Supersolids: what and where are they ?
• Supersolid Order from Disorder: Hard-Core Bosons on the Triangular Lattice
• Persistent supersolid phase of hard-core bosons on the triangular lattice
• Phase separation in supersolids
• Supersolids versus phase separation in two-dimensional lattice bosons
• Absence of supersolidity in solid helium in porous Vycor glass
• Luttinger Liquid in the Core of Screw Dislocation in Helium-4
• Quantum Phases of the Extended Bose-Hubbard Hamiltonian: Possibility of a Supersolid State of Cold Atoms in Optical Lattices
• Nature of the quantum phase transitions in the two-dimensional hardcore boson model
• Supersolids in the Bose-Hubbard Hamiltonian
• Finite-Temperature Phase Diagram of Hard-Core Bosons in Two Dimensions
• Simultaneous Diagonal and Off Diagonal Order in the Bose--Hubbard Hamiltonian
• Searching for a Supersolid in Cold Atom Optical Lattices
• Directed Loop Updates for Quantum Lattice Models
• Supersolidity from defect-condensation in the extended boson Hubbard model
• Variational wavefunction study of the triangular lattice supersolid
• Supersolid phases in the extended boson hubbard model
• Experimental observation of the crystallization of a paired holon state
• Phase diagram of one-dimensional Hubbard-Holstein model at quarter-filling
• Supersolid Phase Accompanied by a Quantum Critical Point in the Intermediate Coupling Regime of the Holstein Model
• Numerical study of magnetic field induced ordering in BaCuSi${}_2$O${}_6$ and related systems
• A study of cooperative breathing-mode in molecular chains