Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:cond-mat/0404561 · Journal of Experimental and Theoretical Physics Letters

Topological phase separation in 2D hard-core Bose-Hubbard system away from half-filling

A. S. Moskvin, I. G. Bostrem, A. S. Ovchinnikov

Published Dec 1, 2003• 15 citations
arXivHTMLPDF

Abstract

We suppose that the doping of the 2D hard-core boson system away from half-filling may result in the formation of a multicenter topological defect such as charge order (CO) bubble domain(s) with Bose superfluid (BS) and extra bosons both localized in domain wall(s), or a topological CO + BS phase separation , rather than a uniform mixed CO + BS supersolid phase. Starting from the classical model, we predict the properties of the respective quantum system. The long-wavelength behavior of the system is believed to resemble that of granular superconductors, CDW materials, Wigner crystals, and multiskyrmion system akin in a quantum Hall ferromagnetic state of a 2D electron gas.

DOI
10.1134/1.1664002

Related papers

Topological phase separation in a two-dimensional quantum lattice Bose-Hubbard system away from half-filling

Alexander S. Moskvin

We suppose that the doping of the two-dimensional (2D) hard-core (hc) boson system away from half-filling may result in the formation of a multicenter topological inhomogeneity (defect), such as charge order (CO) bubble domain(s) with Bose superfluid (BS) and extra bosons both localized in domain wall(s), or else in a topological $\text{CO}+\text{BS}$ phase separation rather than a uniform mixed $\text{CO}+\text{BS}$ supersolid phase. Starting from the classical model, we predict the properties of the respective quantum system. The long-wavelength behavior of the system is believed to be reminiscent of that of granular superconductors, charge-density wave materials, Wigner crystals, and multi-Skyrmion systems akin to the quantum Hall ferromagnetic state of a 2D electron gas. To elucidate the role played by quantum effects and that of the lattice discreteness, we have addressed the simplest nanoscopic counterpart of the bubble domain in the checkerboard CO phase of a 2D hc Bose-Hubbard (BH) square lattice. It is shown that the relative magnitude and symmetry of a multicomponent order parameter are mainly determined by the sign of the nearest-neighbor and next-nearest-neighbor transfer integrals. In general, the topologically inhomogeneous phase of the hc-BH system away from the half-filling can exhibit the signatures of the $s$, $d$, and $p$ symmetries of the off-diagonal order.

arXiv:cond-mat/0404562•Physical Review B•Jun 11, 2004•18 citations

Supersolidity from defect condensation in the extended boson Hubbard model

Yi‐Chun Chen, Roger G. Melko, Stefan Weßel +1 more

We study the ground-state phase diagram of the hard-core extended boson Hubbard model on the square lattice with both nearest- and next-nearest-neighbor hoppings and repulsions, using Gutzwiller mean-field theory and quantum Monte Carlo simulations. We observe the formation of supersolid states with checkerboard, striped, and quarter-filled crystal structures when the system is doped away from commensurate fillings. In the striped supersolid phase, a strong anisotropy in the superfluid density is obtained from the simulations; however, the transverse component remains finite, indicating a true two-dimensional superflow. We find that upon doping, the striped supersolid transitions directly into the supersolid with quarter-filled crystal structure, via a first-order stripe melting transition.

arXiv:0708.1807•Physical Review B•Jan 28, 2008•57 citations

Quantum Domain Walls Induce Incommensurate Supersolid Phase on the Anisotropic Triangular Lattice

Xue‐Feng Zhang, Shijie Hu, Axel Pelster +1 more

We investigate the extended hard-core Bose-Hubbard model on the triangular lattice as a function of spatial anisotropy with respect to both hopping and nearest-neighbor interaction strength. At half-filling the system can be tuned from decoupled one-dimensional chains to a two-dimensional solid phase with alternating density order by adjusting the anisotropic coupling. At intermediate anisotropy, however, frustration effects dominate and an incommensurate supersolid phase emerges, which is characterized by incommensurate density order as well as an anisotropic superfluid density. We demonstrate that this intermediate phase results from the proliferation of topological defects in the form of quantum bosonic domain walls. Accordingly, the structure factor has peaks at wave vectors, which are linearly related to the number of domain walls in a finite system in agreement with extensive quantum Monte Carlo simulations. We discuss possible connections with the supersolid behavior in the high-temperature superconducting striped phase.

arXiv:1605.01237•Physical Review Letters•Nov 3, 2016•25 citations

Quantum phase transition in Bose-Holstein model in two dimensions

Sanjoy Datta, Sudhakar Yarlagadda

We derive an effective d-dimensional Hamiltonian for a system of hard-core-bosons coupled to optical phonons in a lattice. Away from half-filling, we show that the presence of next-nearest-neighbor hopping in the effective Hamiltonian leads to a superfluid-to-supersolid transition at intermediate boson-phonon (b-p) couplings, while at strong-couplings the system phase separates. However, at half-filling and at a critical b-p coupling (as in the xxz-model), the system undergoes a superfluid-to-charge-density-wave transition without any signature of supersolidity. Our analyses is based on extensive calculations of the structure factor, the superfluid fraction, the Bose-Einstein condensate fraction, and the system energy at various fillings. We present a phase diagram for this system and compare it to that of the xxz-model. We also demonstrate explicitly that the next-nearest-neighbor hopping (in the absence of nearest-neighbor hopping) in the effective Hamiltonian leads only to a single transition, i.e., a first-order superfluid-to-supersolid transition.

arXiv:0812.1987•Dec 10, 2008•1 citation

Charge order–superfluidity transition in a two-dimensional system of hard-core bosons and emerging domain structures

Alexander S. Moskvin, Yu. D. Panov, Filipp N. Rybakov +1 more

We have used high-performance parallel computations by NVIDIA graphics cards applying the method of nonlinear conjugate gradients and Monte Carlo method to observe directly the developing ground state configuration of a two-dimensional hard-core boson system with decrease in temperature, and its evolution with deviation from a half-filling. This has allowed us to explore unconventional features of a charge order—superfluidity phase transition, specifically, formation of an irregular domain structure, emergence of a filamentary superfluid structure that condenses within of the charge-ordered phase domain antiphase boundaries, and formation and evolution of various topological structures.

Physics of the Solid State•Nov 1, 2017•0 citations

Complex phases in the doped two-species bosonic Hubbard model

Kalani Hettiarachchilage, V. G. Rousseau, Ka-Ming Tam +2 more

We study a doped two-dimensional bosonic Hubbard model with two hard-core species using quantum Monte Carlo simulations. With doping we find five distinct phases, including a normal liquid at higher temperature, an antiferromagnetically ordered Mott insulator, a region of coexistent antiferromagnetic and superfluid phases near half filling, and farther away from half filling, a superfluid phase and a phase-separated ferromagnet. In the latter, the heavy species has Mott behavior with integer fillings, while the light species shows Mott and superfluid behaviors. The global entropy of this phase is relatively high which may provide a new avenue to obtain a polarized phase or a Mott insulator in cold-atom experiments.

arXiv:1212.4478•Physical Review B•Oct 4, 2013•5 citations
We suppose that the doping of the 2D hard-core boson system away from half-filling may result in the formation of a multicenter topological defect such as charge order (CO) bubble domain(s) with Bose superfluid (BS) and extra bosons both localized in domain wall(s), or a topological CO + BS phase separation , rather than a uniform mixed CO + BS supersolid phase. Starting from the classical model, we predict the properties of the respective quantum system. The long-wavelength behavior of the system is believed to resemble that of granular superconductors, CDW materials, Wigner crystals, and multiskyrmion system akin in a quantum Hall ferromagnetic state of a 2D electron gas.
We suppose that the doping of the two-dimensional (2D) hard-core (hc) boson system away from half-filling may result in the formation of a multicenter topological inhomogeneity (defect), such as charge order (CO) bubble domain(s) with Bose superfluid (BS) and extra bosons both localized in domain wall(s), or else in a topological CO+BS\text{CO}+\text{BS}CO+BS phase separation rather than a uniform mixed CO+BS\text{CO}+\text{BS}CO+BS supersolid phase. Starting from the classical model, we predict the properties of the respective quantum system. The long-wavelength behavior of the system is believed to be reminiscent of that of granular superconductors, charge-density wave materials, Wigner crystals, and multi-Skyrmion systems akin to the quantum Hall ferromagnetic state of a 2D electron gas. To elucidate the role played by quantum effects and that of the lattice discreteness, we have addressed the simplest nanoscopic counterpart of the bubble domain in the checkerboard CO phase of a 2D hc Bose-Hubbard (BH) square lattice. It is shown that the relative magnitude and symmetry of a multicomponent order parameter are mainly determined by the sign of the nearest-neighbor and next-nearest-neighbor transfer integrals. In general, the topologically inhomogeneous phase of the hc-BH system away from the half-filling can exhibit the signatures of the sss, ddd, and ppp symmetries of the off-diagonal order.
We study the ground-state phase diagram of the hard-core extended boson Hubbard model on the square lattice with both nearest- and next-nearest-neighbor hoppings and repulsions, using Gutzwiller mean-field theory and quantum Monte Carlo simulations. We observe the formation of supersolid states with checkerboard, striped, and quarter-filled crystal structures when the system is doped away from commensurate fillings. In the striped supersolid phase, a strong anisotropy in the superfluid density is obtained from the simulations; however, the transverse component remains finite, indicating a true two-dimensional superflow. We find that upon doping, the striped supersolid transitions directly into the supersolid with quarter-filled crystal structure, via a first-order stripe melting transition.
We investigate the extended hard-core Bose-Hubbard model on the triangular lattice as a function of spatial anisotropy with respect to both hopping and nearest-neighbor interaction strength. At half-filling the system can be tuned from decoupled one-dimensional chains to a two-dimensional solid phase with alternating density order by adjusting the anisotropic coupling. At intermediate anisotropy, however, frustration effects dominate and an incommensurate supersolid phase emerges, which is characterized by incommensurate density order as well as an anisotropic superfluid density. We demonstrate that this intermediate phase results from the proliferation of topological defects in the form of quantum bosonic domain walls. Accordingly, the structure factor has peaks at wave vectors, which are linearly related to the number of domain walls in a finite system in agreement with extensive quantum Monte Carlo simulations. We discuss possible connections with the supersolid behavior in the high-temperature superconducting striped phase.
We derive an effective d-dimensional Hamiltonian for a system of hard-core-bosons coupled to optical phonons in a lattice. Away from half-filling, we show that the presence of next-nearest-neighbor hopping in the effective Hamiltonian leads to a superfluid-to-supersolid transition at intermediate boson-phonon (b-p) couplings, while at strong-couplings the system phase separates. However, at half-filling and at a critical b-p coupling (as in the xxz-model), the system undergoes a superfluid-to-charge-density-wave transition without any signature of supersolidity. Our analyses is based on extensive calculations of the structure factor, the superfluid fraction, the Bose-Einstein condensate fraction, and the system energy at various fillings. We present a phase diagram for this system and compare it to that of the xxz-model. We also demonstrate explicitly that the next-nearest-neighbor hopping (in the absence of nearest-neighbor hopping) in the effective Hamiltonian leads only to a single transition, i.e., a first-order superfluid-to-supersolid transition.
We have used high-performance parallel computations by NVIDIA graphics cards applying the method of nonlinear conjugate gradients and Monte Carlo method to observe directly the developing ground state configuration of a two-dimensional hard-core boson system with decrease in temperature, and its evolution with deviation from a half-filling. This has allowed us to explore unconventional features of a charge order—superfluidity phase transition, specifically, formation of an irregular domain structure, emergence of a filamentary superfluid structure that condenses within of the charge-ordered phase domain antiphase boundaries, and formation and evolution of various topological structures.
We study a doped two-dimensional bosonic Hubbard model with two hard-core species using quantum Monte Carlo simulations. With doping we find five distinct phases, including a normal liquid at higher temperature, an antiferromagnetically ordered Mott insulator, a region of coexistent antiferromagnetic and superfluid phases near half filling, and farther away from half filling, a superfluid phase and a phase-separated ferromagnet. In the latter, the heavy species has Mott behavior with integer fillings, while the light species shows Mott and superfluid behaviors. The global entropy of this phase is relatively high which may provide a new avenue to obtain a polarized phase or a Mott insulator in cold-atom experiments.