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

Journal of the Physical Society of Japan

Quantum Monte Carlo Study of Hard-Core Bosons on the Anisotropic Triangular Lattice

Jing-Yu Gan, Jing-Fu Gan

Published Sep 10, 2009• 2 citations
Publisher

Abstract

We study the ground state properties of the extended hard-core Bose–Hubbard model in a two-dimensional anisotropic triangular lattice by quantum Monte Carlo simulations. We present the ground state phase diagram at half filling. Four kinds of phases, including two solid phases, a superfluid phase and a supersolid phase, are observed. The supersolid phase exists only in a narrow region close to the isotropic limit. Away from half filling, we find that the results are strongly dependent on the phase at half filling. No supersolid phase exists if the ground state at half filling is a superfluid or a solid.

DOI
10.1143/jpsj.78.094602

Related papers

Supersolidity and phase diagram of soft-core bosons on a triangular lattice

Jing-Yu Gan, Yu-Chuan Wen, Yue Yu

We study the soft-core extended Bose-Hubbard model in a two-dimensional triangular lattice by using the quantum Monte Carlo methods. The ground-state phase diagram of the system exhibits a very fruitful structure and is much intriguing. Aside from the Mott insulating state, four kinds of solid states with respect to the commensurate filling factors $\ensuremath{\rho}=1∕3,2∕3$ and $\ensuremath{\rho}=1$ are identified. In incommensurate fillings, superfluid, supersolid, as well as phase-separation states are detected. As in the case of the hard-core bosons, a supersolid phase exists in $1∕3<\ensuremath{\rho}<2∕3$ while it is unstable toward the phase separation in $\ensuremath{\rho}<1∕3$. However, this instability is refrained in $2∕3<\ensuremath{\rho}<1$ due to the softening of the bosons, and then a supersolid phase survives.

arXiv:cond-mat/0609492•Physical Review B•Mar 1, 2007•24 citations

Quantum phases of hard-core bosons on two-dimensional lattices with anisotropic dipole-dipole interaction

Takahiro Ohgoe, Takafumi Suzuki, Naoki Kawashima

By using an unbiased quantum Monte Carlo method, we investigate the hard-core Bose-Hubbard model on a square lattice with the anisotropic dipole-dipole interaction. To study the effect of the anisotropy, dipole moments are assumed to be polarized in the $y$ direction on the two-dimensional $xy$ plane. To perform efficient simulations of long-range interacting systems, we use the worm algorithm with an $O(N)$ Monte Carlo method. We obtain the ground-state phase diagram that includes a superfluid phase and a striped solid phase at half-filling as two main phases. In addition to these two main phases, we find a small region where there are multiple plateaus in the particle density for small hopping amplitudes. In this region, the number of plateaus increases as the system size increases. This indicates the appearance of numerous competing ground states due to frustrated interactions. In our simulations, we find no evidence of a supersolid phase.

arXiv:1110.2109•Physical Review A•Dec 26, 2012•19 citations

Effects of frustration on the anisotropic triangular lattice bosons

Jing-Yu Gan

We study the extended hard-core Bose-Hubbard model with nearest-neighbor interactions on a triangular lattice with spatial anisotropy by quantum Monte Carlo simulations. The effects of the geometric frustration or the anisotropic strength, represented by the ratio ${t}^{\ensuremath{'}}/t$ between the intrachain nearest-neighbor hopping ${t}^{\ensuremath{'}}$ and the interchain hopping $t$, are studied. We find that for small values of anisotropy ratio ${t}^{\ensuremath{'}}/t$, a solid state emerges at $\ensuremath{\rho}=1/2$ and a supersolid is unstable toward phase separation; for large values of anisotropy ratio ${t}^{\ensuremath{'}}/t$, solid states emerge at $\ensuremath{\rho}=1/3$, 2/3, and a supersolid phase is stable in the region $\ensuremath{\rho}<2/3$; for intermediate values of anisotropy ratio ${t}^{\ensuremath{'}}/t$, three kinds of solid states at fillings $\ensuremath{\rho}=1/3$, 1/2, and $\ensuremath{\rho}=2/3$ coexist and no stable supersolid phase is observed. At half filling, we find that with increasing frustration ${t}^{\ensuremath{'}}/t$, the $\ensuremath{\rho}=1/2$ solid transitions indirectly into the supersolid via an intervening superfluid.

Physical Review B•Jul 17, 2008•6 citations

Quantum Monte Carlo Study of Hard-Core Bosons on the Shastry–Sutherland Lattice

Jing-Yu Gan

We study the ground state properties of the extended hard-core Bose–Hubbard model in a two-dimensional Shastry–Sutherland lattice by quantum Monte Carlo simulations. The effects of the geometric frustration, described by the ratio t ′ / t between hopping integrals along the nearest-neighbor links and the diagonal links, are studied. We find that for small values of frustration amplitude t ′ / t , a checkerboard solid state emerges at ρ= 1/2; for large values of frustration amplitude t ′ / t , a solid state emerges at ρ= 1/2 with one boson per dimer (dimers on diagonal links); for intermediate values of frustration amplitude t ′ / t , besides the ρ= 1/2 solid state, the ρ= 1/3,2/3 solid states emerge. No stable supersolid state is observed in our calculations. At half filling, we find solid-superfluid-solid phase transition as the frustration amplitude t ′ / t is increased.

Journal of the Physical Society of Japan•Mar 10, 2011•2 citations

Ground-state phase diagram of the two-dimensional extended Bose-Hubbard model

Takahiro Ohgoe, Takafumi Suzuki, Naoki Kawashima

We investigate the ground-state phase diagram of the soft-core Bose-Hubbard model with the nearest-neighbor repulsion on a square lattice by using an unbiased quantum Monte Carlo method. In contrast to a previous study [P. Sengupta et al., Phys. Rev. Lett. 94, 207202 (2005)], we present the ground-state phase diagrams up to high hopping amplitudes. As a result, in addition to the known supersolid above half-filling, we find a supersolid phase below and at half-filling for high hopping amplitudes. In addition, for a strong nearest-neighbor repulsion, we show that the supersolid phase occupies a remarkably broad region in the phase diagram. These results are in agreement with the results of the Gutzwiller mean-field approximation [M. Iskin, Phys. Rev. A 83, 051606(R) (2011); T. Kimura, Phys. Rev. A 84, 063630 (2011)]. However, it turns out that the regions of the supersolid phases are significantly smaller than the mean-field results.

arXiv:1206.3670•Physical Review B•Aug 27, 2012•55 citations

Extended Bose-Hubbard model on a honeycomb lattice

Jing Yu Gan, Yu Chuan Wen, Jinwu Ye +3 more

We study the extended Bose-Hubbard model on a two-dimensional honeycomb lattice by using large-scale quantum Monte Carlo simulations. We present the ground-state phase diagrams for both the hard-core and the soft-core bosons. For the hard-core case, the transition between the $\ensuremath{\rho}=1∕2$ solid and the superfluid is first order, and the supersolid state is unstable toward phase separation. For the soft-core case, due to the presence of multiple occupation, a stable particle-induced supersolid (SS-p) phase emerges when $1∕2<\ensuremath{\rho}<1$. The transition from the solid at $\ensuremath{\rho}=1∕2$ to the SS-p phase is second order with the superfluid density scaling as ${\ensuremath{\rho}}_{s}\ensuremath{\sim}\ensuremath{\rho}\ensuremath{-}1∕2$. The SS-p phase has the same diagonal order as the solid at $\ensuremath{\rho}=1∕2$. As the chemical potential increases further, the SS-p phase turns into a solid where two bosons occupy each site of one sublattice through a first-order transition. We also calculate the critical exponents of the transition between the $\ensuremath{\rho}=1∕2$ solid and superfluid at the Heisenberg point for the hard-core case. We find the dynamical critical exponent $z=0.15$, which is smaller than results obtained on smaller lattices. This indicates that $z$ approaches zero in the thermodynamic limit, and thus the transition is also first order even at the Heisenberg point.

arXiv:cond-mat/0701120•Physical Review B•Jun 15, 2007•37 citations
We study the ground state properties of the extended hard-core Bose–Hubbard model in a two-dimensional anisotropic triangular lattice by quantum Monte Carlo simulations. We present the ground state phase diagram at half filling. Four kinds of phases, including two solid phases, a superfluid phase and a supersolid phase, are observed. The supersolid phase exists only in a narrow region close to the isotropic limit. Away from half filling, we find that the results are strongly dependent on the phase at half filling. No supersolid phase exists if the ground state at half filling is a superfluid or a solid.
We study the soft-core extended Bose-Hubbard model in a two-dimensional triangular lattice by using the quantum Monte Carlo methods. The ground-state phase diagram of the system exhibits a very fruitful structure and is much intriguing. Aside from the Mott insulating state, four kinds of solid states with respect to the commensurate filling factors $\ensuremath{\rho}=1∕3,2∕3$ and $\ensuremath{\rho}=1$ are identified. In incommensurate fillings, superfluid, supersolid, as well as phase-separation states are detected. As in the case of the hard-core bosons, a supersolid phase exists in $1∕3<\ensuremath{\rho}<2∕3$ while it is unstable toward the phase separation in $\ensuremath{\rho}<1∕3$. However, this instability is refrained in $2∕3<\ensuremath{\rho}<1$ due to the softening of the bosons, and then a supersolid phase survives.
By using an unbiased quantum Monte Carlo method, we investigate the hard-core Bose-Hubbard model on a square lattice with the anisotropic dipole-dipole interaction. To study the effect of the anisotropy, dipole moments are assumed to be polarized in the yyy direction on the two-dimensional xyxyxy plane. To perform efficient simulations of long-range interacting systems, we use the worm algorithm with an O(N)O(N)O(N) Monte Carlo method. We obtain the ground-state phase diagram that includes a superfluid phase and a striped solid phase at half-filling as two main phases. In addition to these two main phases, we find a small region where there are multiple plateaus in the particle density for small hopping amplitudes. In this region, the number of plateaus increases as the system size increases. This indicates the appearance of numerous competing ground states due to frustrated interactions. In our simulations, we find no evidence of a supersolid phase.
We study the extended hard-core Bose-Hubbard model with nearest-neighbor interactions on a triangular lattice with spatial anisotropy by quantum Monte Carlo simulations. The effects of the geometric frustration or the anisotropic strength, represented by the ratio ${t}^{\ensuremath{'}}/t$ between the intrachain nearest-neighbor hopping ${t}^{\ensuremath{'}}$ and the interchain hopping ttt, are studied. We find that for small values of anisotropy ratio ${t}^{\ensuremath{'}}/t$, a solid state emerges at $\ensuremath{\rho}=1/2$ and a supersolid is unstable toward phase separation; for large values of anisotropy ratio ${t}^{\ensuremath{'}}/t$, solid states emerge at $\ensuremath{\rho}=1/3$, 2/3, and a supersolid phase is stable in the region $\ensuremath{\rho}<2/3$; for intermediate values of anisotropy ratio ${t}^{\ensuremath{'}}/t$, three kinds of solid states at fillings $\ensuremath{\rho}=1/3$, 1/2, and $\ensuremath{\rho}=2/3$ coexist and no stable supersolid phase is observed. At half filling, we find that with increasing frustration ${t}^{\ensuremath{'}}/t$, the $\ensuremath{\rho}=1/2$ solid transitions indirectly into the supersolid via an intervening superfluid.
We study the ground state properties of the extended hard-core Bose–Hubbard model in a two-dimensional Shastry–Sutherland lattice by quantum Monte Carlo simulations. The effects of the geometric frustration, described by the ratio t ′ / t between hopping integrals along the nearest-neighbor links and the diagonal links, are studied. We find that for small values of frustration amplitude t ′ / t , a checkerboard solid state emerges at ρ= 1/2; for large values of frustration amplitude t ′ / t , a solid state emerges at ρ= 1/2 with one boson per dimer (dimers on diagonal links); for intermediate values of frustration amplitude t ′ / t , besides the ρ= 1/2 solid state, the ρ= 1/3,2/3 solid states emerge. No stable supersolid state is observed in our calculations. At half filling, we find solid-superfluid-solid phase transition as the frustration amplitude t ′ / t is increased.
We investigate the ground-state phase diagram of the soft-core Bose-Hubbard model with the nearest-neighbor repulsion on a square lattice by using an unbiased quantum Monte Carlo method. In contrast to a previous study [P. Sengupta et al., Phys. Rev. Lett. 94, 207202 (2005)], we present the ground-state phase diagrams up to high hopping amplitudes. As a result, in addition to the known supersolid above half-filling, we find a supersolid phase below and at half-filling for high hopping amplitudes. In addition, for a strong nearest-neighbor repulsion, we show that the supersolid phase occupies a remarkably broad region in the phase diagram. These results are in agreement with the results of the Gutzwiller mean-field approximation [M. Iskin, Phys. Rev. A 83, 051606(R) (2011); T. Kimura, Phys. Rev. A 84, 063630 (2011)]. However, it turns out that the regions of the supersolid phases are significantly smaller than the mean-field results.
We study the extended Bose-Hubbard model on a two-dimensional honeycomb lattice by using large-scale quantum Monte Carlo simulations. We present the ground-state phase diagrams for both the hard-core and the soft-core bosons. For the hard-core case, the transition between the $\ensuremath{\rho}=1∕2$ solid and the superfluid is first order, and the supersolid state is unstable toward phase separation. For the soft-core case, due to the presence of multiple occupation, a stable particle-induced supersolid (SS-p) phase emerges when $1∕2<\ensuremath{\rho}<1$. The transition from the solid at $\ensuremath{\rho}=1∕2$ to the SS-p phase is second order with the superfluid density scaling as ${\ensuremath{\rho}}_{s}\ensuremath{\sim}\ensuremath{\rho}\ensuremath{-}1∕2$. The SS-p phase has the same diagonal order as the solid at $\ensuremath{\rho}=1∕2$. As the chemical potential increases further, the SS-p phase turns into a solid where two bosons occupy each site of one sublattice through a first-order transition. We also calculate the critical exponents of the transition between the $\ensuremath{\rho}=1∕2$ solid and superfluid at the Heisenberg point for the hard-core case. We find the dynamical critical exponent z=0.15z=0.15z=0.15, which is smaller than results obtained on smaller lattices. This indicates that zzz approaches zero in the thermodynamic limit, and thus the transition is also first order even at the Heisenberg point.