Article
Physics, Multidisciplinary
Zhenjiu Wang, Yuhai Liu, Toshihiro Sato, Martin Hohenadler, Chong Wang, Wenan Guo, Fakher F. Assaad
Summary: The study reveals new properties of the quantum spin Hall insulating state, paving the way for superconductivity through the condensation of skyrmions. Through simulations, it is confirmed that there is a direct transition between the quantum spin Hall insulator and an s-wave superconductor, with the ability to analyze dopings away from half-filling. This route to superconductivity has been proposed in the realm of twisted bilayer graphene.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Condensed Matter
Shuhui Yang, Tao Ying, Wei-Qi Li, Jianqun Yang, Xiudong Sun, Xingji Li
Summary: Using the DQMC algorithm, we studied the pairing symmetries of the Hubbard Hamiltonian on square lattices with next-nearest-neighbor hopping t'. We found that d-wave pairing is suppressed by t' while p + ip-wave pairing tends to emerge for low electron density and specific values of t'. By calculating spin correlation functions, we explored the connections between anti-ferromagnetic/ferromagnetic orders and different pairing symmetries.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2021)
Article
Computer Science, Interdisciplinary Applications
Yuichi Motoyama, Kazuyoshi Yoshimi, Akiko Masaki-Kato, Takeo Kato, Naoki Kawashima
Summary: The Discrete Space Quantum Systems Solver (DSQSS) is a program package for solving quantum many-body problems on lattices, using the quantum Monte Carlo method in Feynman's path integral representation. It covers a broad range of problems and allows for finite temperature calculations of quantum spin and the Bose-Hubbard models by specifying parameters such as dimensions, lattice size, coupling constants, and temperature.
COMPUTER PHYSICS COMMUNICATIONS
(2021)
Article
Materials Science, Multidisciplinary
Chenyue Wen, Wanpeng Han, Xukun Feng, Xingchuan Zhu, Weisheng Zhao, Shengyuan A. Yang, Shiping Feng, Huaiming Guo
Summary: In this study, the antiferromagnetic (AFM) transitions of birefringent Dirac fermions in graphene are investigated. The results show that the quantum critical point can be continuously tuned by the bond-modulation strength, and the critical interaction scales with the geometric average of the two velocities of the birefringent Dirac cones.
Article
Chemistry, Medicinal
Alexander Zech, Timur Bazhirov
Summary: This article presents an effort to organize the diverse landscape of physics-based and data-driven computational models in order to facilitate the storage of associated information as structured data. The authors apply object-oriented design concepts and propose an open-source collaborative framework that can uniquely describe methods, cover widely used models, and utilize collective intelligence.
JOURNAL OF CHEMICAL INFORMATION AND MODELING
(2022)
Article
Chemistry, Physical
Oliver A. Bramley, Timothy J. H. Hele, Dmitrii Shalashilin
Summary: Zombie states are a formalism that describes coupled coherent fermionic states in a computationally tractable manner. This study extends the previous work on Zombie states and develops efficient algorithms for evaluating operators and addressing normalization. It also presents techniques for improving accuracy and calculating low-lying excited states.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Physics, Multidisciplinary
Xiaoyu Wang, Morten H. Christensen, Erez Berg, Rafael M. Fernandes
Summary: This study investigates a class of two-dimensional two-band microscopic models with dominant inter-band repulsive interactions, proposing constrained schemes to overcome the fermionic sign-problem for efficient Quantum Monte Carlo simulations. The behavior of the models in the strong-coupling regime is studied, revealing a variety of ground states and quantum critical points accessible by varying the band structure parameters. The comparison with the single-band Hubbard model shows differences in strong-coupling behavior.
Article
Physics, Condensed Matter
Xingchuan Zhu, Jiaojiao Guo, Nikolas P. Breuckmann, Huaiming Guo, Shiping Feng
Summary: By utilizing the extended Bose-Hubbard model on hyperbolic lattices, the study examines the impact of many-body interactions, revealing that the Mott lobes decrease in size as q in the Schlafli symbol increases, and the supersolid is stabilized under smaller nearest-neighbor interactions. This phenomenon is attributed to the increase in coordination number, leading to higher kinetic energy and nearest-neighbor interaction. The results propose that hyperbolic lattices could serve as a unique platform for investigating the influence of coordination numbers on quantum phase transitions, which may have implications for experiments involving ultracold atoms in optical lattices.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2021)
Article
Physics, Multidisciplinary
Tom Westerhout, Mikhail I. Katsnelson, Andrey A. Bagrov
Summary: In this study, we focus on the real-valued signful ground-state wave functions of frustrated quantum spin systems. We demonstrate that the signs can be easily recovered from the amplitudes using an auxiliary classical Ising model. Our findings reveal the hidden simplicity of many-body sign structures.
COMMUNICATIONS PHYSICS
(2023)
Article
Physics, Multidisciplinary
Shuhui Yang, Tao Ying, Xiudong Sun
Summary: This study investigates the quantum behaviors of hardcore bosons with finite-range interactions in one-dimensional optical lattices using the Quantum Monte Carlo algorithm. It reveals a phase transition from superfluid to supersolid and finally to CDW phase as the interaction strength increases, while also examining the effects of finite temperature and finite size.
Article
Materials Science, Multidisciplinary
Yuichi Motoyama, Kazuyoshi Yoshimi, Junya Otsuki
Summary: Analytic continuation from the imaginary-time Green's function to the spectral function is crucial for studying the dynamical properties of quantum many-body systems. However, this process is unstable and has advantages and disadvantages. Combining SpM AC with Pade approximation in the SpM-Pade method can provide more accurate and stable results.
Article
Physics, Multidisciplinary
Ke Liu, Shuhui Yang, Weiqi Li, Tao Ying, Jianqun Yang, Xiudong Sun, Xingji Li
Summary: Using finite-temperature determinant quantum Monte Carlo algorithm, the study investigates the effective pairing susceptibility in the two-dimensional Hubbard model, identifying the dominant pairing channels in different parameter regimes. The dominant pairing is found to be d(x2-y2)-wave at half-filling, while in doping cases, the dominant channel may switch between d(x2-y2)-wave and d(xy)-wave.
Article
Chemistry, Physical
Jonas Feldt, Antoine Bienvenu, Roland Assaraf
Summary: In this paper, a new estimator in the variational Monte Carlo framework is proposed, which utilizes numerically cheap single-core subsamplings to improve the estimation of molecular properties. Furthermore, a spin-dependent core definition is introduced to simplify the algorithm and enhance its efficiency.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Giovani L. Rech, Andre L. Martinotto, Janete E. Zorzi, Claudio A. Perottoni
Summary: The relative stability between the crystal structure of alpha-F-2, space group C2/c, and a hypothesized high-pressure phase, space group Cmce, was investigated using Density Functional Theory and Quantum Monte Carlo calculations. The analysis of the phonon dispersion spectra showed that the Cmce phase exhibits dynamical instability near the Gamma-point at ambient pressure, which disappears under increasing pressure. This instability is attributed to the absence of sigma-holes in the fluorine molecule, resulting in repulsive head-to-head interactions between molecules.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Physics, Multidisciplinary
Aaram J. Kim, Nikolay Prokof'ev, Boris Svistunov, Evgeny Kozik
Summary: The major obstacle for Feynman diagrammatic expansions to accurately solve many-fermion systems in strongly correlated regimes is the slow convergence or divergence problem. Different techniques have been proposed to address this issue, with the homotopic action providing a universal and systematic framework for unifying existing and generating new methods.
PHYSICAL REVIEW LETTERS
(2021)