Related papers: Spin-boson coupling in continuous-time quantum Mon…
We formulate a quantum Monte Carlo (QMC) method for calculating the ground state of many-boson systems. The method is based on a field-theoretical approach, and is closely related to existing fermion auxiliary-field QMC methods which are…
Spin-crossover compounds, which are characterized by magnetic ions showing low-spin and high-spin states at thermally accessible energies, are ubiquitous in nature. We here focus on the effect of an exchange interaction on the collective…
We address the phenomenon of critical Kondo destruction in pseudogap Bose-Fermi Anderson and Kondo quantum impurity models. These models describe a localized level coupled both to a fermionic bath having a density of states that vanishes…
We study the stability of solid- and supersolid (SS) phases of a three-dimensional spin- and a hardcore-Bose-Hubbard models on a body-centered cubic lattice. To see the quantum effects on the stability of the SS phase, we model the…
Thermodynamics of a spin-1 Bose gas with ferromagnetic interactions are investigated via the mean-field theory. It is apparently shown in the specific heat curve that the system undergoes two phase transitions, the ferromagnetic transition…
We study the quantum dynamics of a spin-orbit (SO) coupled Bose-Einstein condensate (BEC) in a double-well potential inspired by the experimental protocol recently developed by NIST group. We focus on the regime where the number of atoms is…
Ultracold bosons in optical lattices are one of the few systems where bosonic matter is known to exhibit strong correlations. Here we push the frontier of our understanding of interacting bosons in optical lattices by adding synthetic…
We study a model describing electrons coupled to anti-ferromagnetic spin fluctuations, and consider the situation where hedgehog defects in the order parameter field are suppressed. Without hedgehogs, the bosonic sector of the theory can be…
The annihilation of two intermediate-coupling renormalization-group (RG) fixed points is of interest in diverse fields from statistical mechanics to high-energy physics, but has so far only been studied using perturbative techniques. Here…
We study a statistical mechanics model of two species of bosons with mutual statistics $\theta=2\pi/n$ in (2+1) dimensions. This model realizes a fractionalized topological phase of bosons, which is a fractionalized version of the boson…
Motivated by the unconventional superconductivity observed in heavy-fermion metals, we investigate pairing susceptibilities near a continuous quantum phase transition of the Kondo-destruction type. We solve two-impurity Bose-Fermi Anderson…
Study of dissipative quantum phase transitions in the Ohmic spin-boson model is numerically challenging in a dense limit of environmental modes. In this work, large-scale numerical simulations are carried out based on the variational…
The ground states of Bose-Einstein condensates of spin-2 bosons are classified into three distinct (ferromagnetic, ^^ ^^ antiferromagnetic", and cyclic) phases depending on the s-wave scattering lengths of binary collisions for total-spin…
Spin-orbit (SO) coupling -- the interaction between a quantum particle's spin and its momentum -- is ubiquitous in nature, from atoms to solids. In condensed matter systems, SO coupling is crucial for the spin-Hall effect and topological…
We consider a class of generalised single mode Dicke Hamiltonians with arbitrary boson coupling in the pseudo-spin $x$-$z$ plane. We find exact solutions in the thermodynamic, large-spin limit as a function of the coupling angle, which…
We combine model mapping, exact spectral bounds, and a quantum Monte Carlo method to study the ground state phases of a mixture of ultracold bosons and spin-polarized fermions in a one-dimensional optical lattice. The exact boundary of the…
The Bose-Fermi Kondo model captures the physics of the destruction of Kondo screening, which is of extensive current interest to the understanding of quantum critical heavy fermion metals. There are presently limited theoretical methods to…
The low-temperature properties of a 2D Bose fluid of charged particles interacting through a 1/r potential, moving in the presence of a uniform neutralizing background, is studied by Quantum Monte Carlo simulations. We make use of the…
We theoretically study homogeneously trapped atomic Bose-Einstein condensates where all three momentum components couple to a pseudo-spin-$1/2$ degree of freedom. Tuning the anisotropies of spin-orbit coupling and the spin-dependent…
The coherent transport through a set of N quantum dots coupled in parallel is considered in the limit of infinite intradot and finite or infinite interdot interactions. The mean field slave boson approach and the equation of motion method…