Article
Materials Science, Multidisciplinary
C. G. L. Bottcher, F. Nichele, J. Shabani, C. J. Palmstrom, C. M. Marcus
Summary: In this study, we explore the vortex dynamics in a two-dimensional Josephson junction array. We observe that the minima of differential resistance undergo a transition and become local maxima at integer and half-integer flux quanta per plaquette. We also observe differences in the transition behavior between the superconducting and anomalous metal phases. Additionally, we find that the transitions show an overall even-odd pattern of skewing around integer f values, which we attribute to vortex commensuration in the square array.
Article
Materials Science, Multidisciplinary
Piotr Chudzinski
Summary: The study develops a scheme to calculate the parameters of Tomonaga-Luttinger liquid and holon velocity in quasi-1D materials, focusing on two-leg ladders coupled through Coulomb interactions. By deriving an analytic formula for electron-electron interaction potential and introducing many-body screening, the study is able to determine the TLL's parameters and velocities. Experimental validation using angle-resolved photoemission spectroscopy data in NbSe3 is provided, with the applicability of the scheme to other quasi-1D systems with two-leg ladders as basic units demonstrated.
Article
Multidisciplinary Sciences
Peizhi Mai, Seher Karakuzu, Giovanni Balduzzi, Steven Johnston, Thomas A. Maier
Summary: The observation of fluctuating spin and charge stripes in the doped single-band Hubbard model using a quantum Monte Carlo dynamical cluster approximation (DCA) method demonstrates that they survive in the doped Hubbard model in the thermodynamic limit.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Physics, Multidisciplinary
Minghu Pan, Xin Zhang, Yinong Zhou, Pengdong Wang, Qi Bian, Hang Liu, Xingyue Wang, Xiaoyin Li, Aixi Chen, Xiaoxu Lei, Shaojian Li, Zhengwang Cheng, Zhibin Shao, Haoxuan Ding, Jianzhi Gao, Fangsen Li, Feng Liu
Summary: In this study, we report the surface growth of a self-assembled monolayer of 2D hydrogen-bond organic frameworks (HOFs) on an Au(111) substrate and the observation of flat bands (FBs). The highly ordered THPB HOF domains and the FB over the whole Brillouin zone were observed through high-resolution scanning tunneling microscopy or spectroscopy and angle-resolved photoemission spectroscopy, respectively. Density functional theory calculations and analyses showed that the observed FB arises from a hidden electronic breathing-kagome lattice without atomically breathing bonds.
PHYSICAL REVIEW LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Johannes Mitscherling, Walter Metzner
Summary: In this study, the emergence of non-Hermitian band topology in a two-dimensional metal with planar spiral magnetism is investigated. The research reveals that a momentum-dependent relaxation rate can lead to exceptional points in the Brillouin zone, resulting in pairs of opposite topological charges connected by arc-shaped branch cuts. Additionally, these exceptional points can cause a drastic change in the Fermi surface topology by merging electron and hole pockets at isolated points in the Brillouin zone.
Article
Chemistry, Multidisciplinary
Young-Woo Son, Hosub Jin, Sejoong Kim
Summary: This study examines the electronic properties of a new planar carbon crystal formed by networking biphenylene molecules, revealing novel electronic features such as zone-center saddle points and peculiar type-II Dirac fermionic states among carbon materials. Additionally, possible magnetic instabilities related to low-energy bands are discussed, and the effects of moderate uniaxial strain on the merging of Dirac points with zone-center saddle points are explored.
Article
Physics, Condensed Matter
Debika Debnath, Kuntal Bhattacharyya, Ashok Chatterjee
Summary: The self-trapping transition is investigated in the two-dimensional extended Holstein-Hubbard model, considering both adiabatic and anti-adiabatic cases. A highly accurate phonon state is used as the averaging state to derive an effective electronic Hamiltonian. The system is then solved for weak correlation using the Hartree-Fock mean-field approximation, and for strong correlation, the electronic Hamiltonian is mapped onto an effective t - J model and solved using the Gutzwiller approximation and Zubarev Green's function technique. The self-trapping transition is found to be continuous in the anti-adiabatic regime and discontinuous in the adiabatic regime, across the entire range of Coulomb interaction.
PHYSICA B-CONDENSED MATTER
(2023)
Article
Multidisciplinary Sciences
Ta Tang, Brian Moritz, Cheng Peng, Zhi-Xun Shen, Thomas P. Devereaux
Summary: This study demonstrates that extended electron-phonon coupling is a significant factor in generating the attractive coupling observed in one-dimensional cuprate materials, and can reproduce the spectral features and doping dependence seen in experiments.
NATURE COMMUNICATIONS
(2023)
Article
Optics
Michal Suchorowski, Anna Dawid, Michal Tomza
Summary: The study investigates the properties of two interacting ultracold highly magnetic atoms trapped in a one-dimensional harmonic potential, focusing on the interplay of external magnetic field, spin-spin interaction, and trapping potential on the system's magnetization. By examining the time evolution of observables that could be experimentally observed, the role of indistinguishability and symmetries in the dynamics is demonstrated. The model presented sheds light on the on-site interaction of extended Hubbard models, providing a better understanding of many-body quantum simulators.
Article
Chemistry, Physical
Xiaojuan Ni, Jean-Luc Bredas
Summary: In this study, the electronic structure evolution of Zn-TEP from molecule to chain, COF, and nanotube is investigated using density functional theory calculations. It is found that the frontier molecular orbitals of Zn-TEP have wavevector-independent flat bands in all the periodic systems. The connection between the COF and nanotube is effectively captured using a zone-folding approach. Importantly, the Zn-TEP nanotube exhibits a totally flat lowest conduction band, providing a platform for exploring various many-body phenomena.
CHEMISTRY OF MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
D. V. Kurlov, M. S. Bahovadinov, S. I. Matveenko, A. K. Fedorov, V. Gritsev, B. L. Altshuler, G. V. Shlyapnikov
Summary: We study the one-dimensional Hubbard model for two-component fermions with infinitely strong on-site repulsion in the presence of disorder. The nature of the emerging phases is drastically changed by the type of disorder. Spin-independent disorder can be treated as a single-particle problem with Anderson localization, while spin-dependent disorder leads to a many-body localization-delocalization transition. We find an explicit analytic expression for the matrix elements of the random magnetic field and support the existence of the many-body localization-delocalization transition in this system.
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
Multidisciplinary Sciences
Wei Wu, Xiang Wang, Andre-Marie Tremblay
Summary: In this study, the electronic scattering rate in cuprate superconductors was investigated using cluster generalization of dynamical mean-field theory, revealing the presence of a non-Fermi liquid phase with linear temperature dependence of the scattering rate, originating from antiferromagnetic fluctuations.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Materials Science, Multidisciplinary
Ze Liu, Jing-Yang You, Bo Gu, Sadamichi Maekawa, Gang Su
Summary: In atomic physics, Hund's rule explains the realization of the largest spin and orbital state through the interplay of spin-orbit coupling and Coulomb interactions. This study demonstrates that in ferromagnetic solids, the effective spin-orbit coupling and orbital magnetic moment can be significantly enhanced by a specific factor derived from the two-orbital and five-orbital Hubbard models with spin-orbit coupling. The findings also suggest that spin polarization is preferred over orbital polarization, consistent with experimental observations. The research provides a fundamental understanding of the enhancement of spin-orbit coupling and orbital moment by Coulomb interactions in ferromagnets, with potential applications in spintronics.
Article
Physics, Multidisciplinary
Lorenzo Gotta, Leonardo Mazza, Pascal Simon, Guillaume Roux
Summary: In this study, a simple one-dimensional model of spinless fermions with pair hopping is investigated, revealing a phase where a Luttinger liquid of paired fermions coexists with a Luttinger liquid of unpaired fermions. Extensive numerical density-matrix renormalization-group calculations are performed, supported by a two-fluid model capturing the essence of this coexistence region.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Gaopei Pan, Xu Zhang, Hongyu Lu, Heqiu Li, Bin-Bin Chen, Kai Sun, Zi Yang Meng
Summary: The dynamic and thermodynamic properties of correlated flat-band systems are investigated using momentum-space quantum Monte Carlo and exact diagonalization methods. It is found that the transition from the interaction-driven quantum anomalous Hall (QAH) insulator to the metallic state occurs at a much lower temperature compared to the zero-temperature single-particle gap generated by the long-range Coulomb interaction. This low transition temperature is attributed to the proliferation of excitonic particle-hole excitations, which restores the broken time-reversal symmetry and leads to an enhancement in charge compressibility. Future experiments are proposed to verify these generic thermodynamic characteristics.
PHYSICAL REVIEW LETTERS
(2023)
Article
Crystallography
Samuel Kellar, Ka-Ming Tam, Juana Moreno
Summary: We numerically study a three-dimensional strongly correlated system and find evidence of a separatrix between Fermi liquid and non-Fermi liquid regions by fitting the quasi-particle weight to the marginal Fermi liquid form at finite doping near the putative quantum critical point. Our results suggest the existence of a marginal Fermi liquid and possibly a quantum critical point in the non-symmetry broken solution of the three-dimensional interacting electron systems.
Article
Physics, Multidisciplinary
Zheng Yan, Yan-Cheng Wang, Rhine Samajdar, Subir Sachdev, Zi Yang Meng
Summary: We perform large-scale quantum Monte Carlo simulations on a realistic Hamiltonian of kagome-lattice Rydberg atom arrays and analyze their static and dynamic properties. We find emergent glassy behavior in a region of parameter space between two valence bond solid phases. The extent and phase transitions of this glassy phase as well as its slow time dynamics and experimental considerations for its detection are discussed. Our proposal opens up a new route to studying real-time glassy phenomena and highlights the potential for quantum simulation of distinct phases of quantum matter.
PHYSICAL REVIEW LETTERS
(2023)
Article
Multidisciplinary Sciences
Zheng Yan, Zi Yang Meng
Summary: Based on the path integral formulation of the reduced density matrix, the authors develop a scheme to extract low-lying entanglement spectrum from quantum Monte Carlo simulations. The method is tested on the Heisenberg spin ladder and supports the conjecture on the entanglement spectrum of topological phase. Furthermore, the authors explain the conjecture via the wormhole effect and extend it to systems beyond gapped topological phases.
NATURE COMMUNICATIONS
(2023)
Article
Physics, Multidisciplinary
Zi Hong Liu, Weilun Jiang, Bin-Bin Chen, Junchen Rong, Meng Cheng, Kai Sun, Zi Yang Meng, Fakher F. Assaad
Summary: The fermion disorder operator reveals the entanglement information at quantum critical points, and its scaling behavior varies in different systems. Continuous symmetries can emerge in certain cases.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Multidisciplinary
Meizhen Huang, Zefei Wu, Xu Zhang, Xuemeng Feng, Zishu Zhou, Shi Wang, Yong Chen, Chun Cheng, Kai Sun, Zi Yang Meng, Ning Wang
Summary: The observation of the quantum anomalous Hall effect and nonlocal transport response in twisted bilayer graphene reveals the existence of nontrivial band topology governed by Berry curvature. However, recent works have shown that nonlinear Hall signals in graphene superlattices are caused by extrinsic disorder scattering instead of intrinsic Berry curvature dipole moment. In this study, we report an intrinsic nonlinear Hall effect induced by Berry curvature dipole in high-quality twisted bilayer graphene devices. We also demonstrate that the application of the displacement field can significantly change the direction and amplitude of the nonlinear Hall voltages through a field-induced sliding of the Berry curvature hotspots. Our findings not only establish the dominant role of Berry curvature dipole in generating intrinsic nonlinear Hall signals in graphene superlattices with low disorder densities, but also highlight the potential of twisted bilayer graphene as a sensitive and fine-tunable platform for second harmonic generation and rectification.
PHYSICAL REVIEW LETTERS
(2023)
Article
Quantum Science & Technology
Zheng Yan, Zheng Zhou, Yan-Hua Zhou, Yan-Cheng Wang, Xingze Qiu, Zi Yang Meng, Xue-Feng Zhang
Summary: Simulating lattice gauge theory Hamiltonian and its nontrivial states using programmable quantum devices has gained significant attention. Rydberg atom arrays have shown promise in quantum simulation and computing. While Z(2) lattice gauge theory and topological order have been realized in experiments, progress is being made towards U(1) lattice gauge theory. This study proposes a sweeping quantum annealing protocol for searching ground states among topological sectors, with linear time complexity for the antiferromagnetic transverse field Ising model. This protocol can be implemented on quantum simulation platforms like Rydberg arrays and D-wave annealer, providing an efficient approach for overcoming topological hindrances in quantum optimization and the preparation of quantum topological states.
NPJ QUANTUM INFORMATION
(2023)
Article
Materials Science, Multidisciplinary
Xu Zhang, Gaopei Pan, Bin-Bin Chen, Heqiu Li, Kai Sun, Zi Yang Meng
Summary: We demonstrate that quantum Monte Carlo (QMC) simulations can be used to accurately simulate magic-angle twisted bilayer graphene (TBG) and obtain a precise phase diagram and dynamical properties. The simulations reveal a thermodynamic transition separating the metallic state and a C = 1 correlated Chern insulator-topological Mott insulator (TMI) at the chiral limit and filling v = 1, as well as a pseudogap spectrum slightly above the transition temperature. These results are consistent with recent experimental findings in nonaligned TBG devices.
Article
Physics, Multidisciplinary
Menghan Song, Jiarui Zhao, Chengkang Zhou, Zi Yang Meng
Summary: Using quantum Monte Carlo simulations, the energy spectra of a 2D spin-1/2 Heisenberg model with long-range interactions are computed. The study reveals the range of interaction strengths for different types of energy spectra and how long-range interactions affect the magnon dispersions and dynamical exponents in 2D quantum magnets. The results suggest that low-energy customs for short-range systems need to be modified for long-range systems, which has implications for experimental efforts in quantum simulators and 2D quantum moire materials.
PHYSICAL REVIEW RESEARCH
(2023)
Article
Physics, Fluids & Plasmas
Anshumitra Baul, Nicholas Walker, Juana Moreno, Ka-Ming Tam
Summary: We generalize the application of variational autoencoders to the anisotropic two-dimensional Ising model and provide numerical evidence that a variational autoencoder can be applied to analyze quantum systems. We reproduce the phase diagram without the explicit construction of an order parameter and demonstrate the validity of using a variational autoencoder to characterize anisotropic classical and quantum models.
Article
Materials Science, Multidisciplinary
Xiaoxue Ran, Zheng Yan, Yan-Cheng Wang, Junchen Rong, Yang Qi, Zi Yang Meng
Summary: In this study, by using the sweeping cluster quantum Monte Carlo method, we reveal the complete ground state phase diagram of the fully packed quantum loop model on the square lattice. We find the emergence of a resonating plaquette phase between the lattice nematic (LN) phase and the staggered phase (SP), separated by a first-order transition and the Rokhsar-Kivelson point. Our renormalization group analysis is fully consistent with the order parameter histogram in Monte Carlo simulations. The realization and implication of our phase diagram in Rydberg experiments are proposed.
Article
Materials Science, Multidisciplinary
Yuan Da Liao, Xiao Yan Xu, Zi Yang Meng, Yang Qi
Summary: Recently, there have been many studies on the (2 + 1)D Gross-Neveu criticality of a single Dirac cone using SLAC fermion investigations. While SLAC fermion construction does show a linear energy-momentum relation for all lattice momenta at the noninteracting limit, the question of long-range hopping and its violation of locality on the Gross-Neveu quantum critical point (GN-QCP), which requires short-range interaction, has not been verified. In this study, large-scale quantum Monte Carlo simulations demonstrate that the interaction-driven antiferromagnetic insulator in this case is fundamentally different from that of a purely local pi-flux Hubbard model on the square lattice. Particularly, the antiferromagnetic long-range order undergoes a finite temperature continuous phase transition, seemingly violating the Mermin-Wagner theorem, and smoothly connects to the previously determined GN-QCP. The magnetic excitations inside the antiferromagnetic insulator are gapped without a Goldstone mode, even though the state spontaneously breaks continuous SU (2) symmetry. These unusual findings highlight the fundamental difference between the QCP in SLAC fermion and that of GN-QCP with short-range interaction.
Article
Materials Science, Multidisciplinary
Ting-Tung Wang, Zi Yang Meng
Summary: In this study, the critical exponents of the GNY chiral Ising transition of Dirac fermions coupled with a scalar field were computed using the EMUS-QMC method. The results obtained from a two-dimensional fermion lattice model were consistent with those obtained from the bootstrap and perturbative approaches.
Article
Physics, Multidisciplinary
Chengkang Zhou, Meng -Yuan Li, Zheng Yan, Peng Ye, Zi Yang Meng
Summary: This paper investigates the dynamical signature in the X-cube model in the presence of external Zeeman fields using large-scale quantum Monte Carlo simulation and stochastic analytic continuation. The study reveals the evolution of subdimensional excitations in fracton orders and their behavior under external fields.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Materials Science, Multidisciplinary
Zheng Yan, Zi Yang Meng, David A. Huse, Amos Chan
Summary: The study introduces a height-conserving quantum dimer model and obtains the ground-state phase diagram through quantum Monte Carlo simulations, demonstrating fragmentation in certain Krylov subspaces and potential glassy phenomena.