Article
Optics
M. Iskin, A. Kele
Summary: In this study, we investigate the bound states of N identical bosons described by a multiband Bose-Hubbard model with various hoppings and an attractive on-site interaction. We derive exact integral equations for the dimers, trimers, tetramers, and other multimers using a variational approach and apply them to a one-dimensional sawtooth model with two bands. Our results reveal the presence of off-site dimer states and off-site trimer states, which were not previously observed in the strong-coupling limit. We compare our variational calculations with density matrix renormalization group (DMRG) simulations and find excellent agreement.
Article
Physics, Multidisciplinary
R. S. Souza, Axel Pelster, F. E. A. dos Santos
Summary: This study analyzes the distinction between three different ground states of a system of spinless bosons with short-range interactions subjected to a random potential using the disordered Bose-Hubbard model. The criteria for identifying the superfluid, Mott-insulator, and Bose-glass phases at finite temperatures are discussed, and field theoretical considerations are used to construct a diagrammatic hopping expansion to the Green's function. By summing subsets of diagrams, the condition for long-range correlations leading to the phase boundary between superfluid and insulating phases is found. This analysis goes beyond mean-field theory results for the classification of these different ground states.
NEW JOURNAL OF PHYSICS
(2021)
Article
Optics
Kingshuk Adhikary, Anushree Dey, Arpita Pal, Subhanka Mal, Bimalendu Deb
Summary: In this theoretical study, we investigate the time- and frequency-domain two-particle correlations in a driven-dissipative Bose-Hubbard model near and at a dissipative phase transition. The Hanbury Brown-Twiss (HBT) correlations show oscillations at the transition point due to the imaginary part of the Liouvillian gap, and the Fourier transform provides information on the transition and Liouvillian dynamics. Analyses of the Wigner distribution and frequency peaks illustrate the quantum statistical properties of the model near the phase-transition point.
Article
Optics
Michael Hughes, Axel U. J. Lode, Dieter Jaksch, Paolo Molignini
Summary: With the advancement in controlling and manipulating ultracold magnetic atoms and dipolar molecules, it is now possible to quantum simulate lattice models with strongly interacting dipole-dipole interactions and high densities. However, this study demonstrates that in regimes of strong dipole-dipole interactions and high densities, the continuum system fails to accurately recreate the desired lattice model. Two-band Hubbard models are required to reduce the discrepancies between continuum and lattice descriptions, but significant deviations in the density profile still remain.
Article
Physics, Multidisciplinary
Victor E. Colussi, Fabio Caleffi, Chiara Menotti, Alessio Recati
Summary: We study the effects of quantum fluctuations in the two-component Bose-Hubbard model and generalize the quantum Gutzwiller approach to mixtures. The mean-field ground-state phase diagram and spectrum of elementary excitations are analyzed, with a focus on quantum phase transitions. We investigate the superfluid transport properties and the linear response dynamics to density and spin probes within the quantum critical regimes. We find that quantum fluctuations have a significant impact on the drag between the superfluid species in the system, especially in the vicinity of the paired and antipaired phases absent in the usual one-component Bose-Hubbard model. Additionally, the contributions of quantum corrections to the one-body coherence and density/spin fluctuations are analyzed from the perspective of the collective modes of the system, providing results for the few-body correlations in all regimes of the phase diagram.
Article
Multidisciplinary Sciences
C. Lagoin, U. Bhattacharya, T. Grass, R. W. Chhajlany, T. Salamon, K. Baldwin, L. Pfeiffer, M. Lewenstein, M. Holzmann, F. Dubin
Summary: The Hubbard model is a celebrated theoretical framework in condensed-matter physics. This study implements the extended Bose-Hubbard Hamiltonian by confining semiconductor dipolar excitons in an artificial two-dimensional square lattice, showcasing the characteristic features of checkerboard spatial order.
Article
Optics
Smitha Vishveshwara, David M. Weld
Summary: In the presence of nearest-neighbor pairing, the Bose-Hubbard chain exhibits an unusual gapped Z(2) Ising phase with number fluctuation but no off-diagonal long range order. This phase has a strongly correlated many-body doubly degenerate ground state that can be viewed as a gap-protected macroscopic qubit. The system can be mapped to an anisotropic transverse spin chain in the strongly interacting limit, which is further mapped to the fermionic sister, the Kitaev chain, with zero-energy Majorana bound states. The cold-atom realization of the paired Bose-Hubbard model in a biased zigzag optical lattice with reservoir-induced pairing provides a possible route for experimental Kitaev chain spectroscopy.
Article
Optics
Yabo Li, Dominik Schneble, Tzu-Chieh Wei
Summary: We investigate dynamically coupled one-dimensional Bose-Hubbard models and solve for the wave functions and energies of two-particle eigenstates. Our study reveals the existence of four different continua and three doublon dispersions in the two-particle spectrum of a system with generic interactions. The presence of doublons and their energies depend on the coupling strength between two species of bosons and the interaction strengths. We provide details on the spectrum and properties of two-particle states, and analyze the difference in time evolution under different coupling strengths and the relation between the long-time behavior of the system and the doublon dispersion. These dynamics can be observed in cold atoms and potentially simulated by digital quantum computers.
Article
Physics, Multidisciplinary
Pallavi P. Gaude, Ananya Das, Ramesh Pai
Summary: The CMFT + DMRG method is applied to understand the quantum phases of the one-dimensional Bose-Hubbard models, showing its effectiveness in determining order parameters and correlation functions of large systems.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2022)
Article
Materials Science, Multidisciplinary
Niclas Goetting, Frederik Lohof, Christopher Gies
Summary: In bilayers of semiconducting transition metal dichalcogenides, the twist angle between layers can introduce a periodic potential modulation, leading to correlated states of excitons. The transition between Mott and extended exciton phases is explored using a moire-Bose-Hubbard Hamiltonian, with parameters obtained from Wannier representation and a nonlocal Rytova-Keldysh model for dielectric screening. The predicted emergence of Mott-insulating states in this system suggests the potential of twisted transition metal dichalcogenide heterostructures as quantum simulators.
Article
Optics
Brendan Rhyno, Nathan Lundblad, David C. Aveline, Courtney Lannert, Smitha Vishveshwara
Summary: Inspired by investigations of BECs in the Cold Atom Laboratory aboard the International Space Station, this study examines the thermodynamic properties of shell-shaped BECs under a spherically symmetric bubble trap potential. The evolution of the system from small filled spheres to large, hollow shells is studied by tuning trap parameters, with analysis of the bubble trap spectrum and states to quantify dimensional crossover to quasi-2D physics. The study also evaluates the critical temperature for BEC formation and the cooling process during adiabatic expansion, highlighting the importance of vortex physics in thin shells and caution with semiclassical treatments.
Article
Optics
Seth T. Rittenhouse, P. Giannakeas, Nirav P. Mehta
Summary: This study investigates the two-body scattering of particles in a one-dimensional periodic potential and utilizes a convenient ansatz to separate center-of-mass and relative motion, resulting in a discrete Schrodinger equation resembling a tight-binding model. By defining distinct scattering lengths and discussing collision resonances, the research reveals the interaction between different bands and collision resonances in the excited band.
Article
Multidisciplinary Sciences
Xi Wang, Chengxin Xiao, Heonjoon Park, Jiayi Zhu, Chong Wang, Takashi Taniguchi, Kenji Watanabe, Jiaqiang Yan, Di Xiao, Daniel R. Gamelin, Wang Yao, Xiaodong Xu
Summary: Many-body interactions between carriers play a crucial role in correlated physics. This study demonstrates the ability to highly tune spin-spin interactions between moire-trapped carriers using optical excitation, resulting in ferromagnetic order in WS2/WSe2 moire superlattices. The observed phenomenon adds a dynamic tuning knob to the rich many-body Hamiltonian of moire quantum matter.
Article
Materials Science, Multidisciplinary
M. Wais, J. Kaufmann, M. Battiato, K. Held
Summary: This study computes the scattering rates of electrons in different lattice models using DMFT and BSE. The results show that the agreement between the two methods varies depending on the strength of the interaction, with significant differences observed in the case of strong interaction.
Article
Physics, Multidisciplinary
Matteo Secli, Massimo Capone, Marco Schiro
Summary: We investigate the signatures of a self-trapping transition in a driven-dissipative Bose Hubbard dimer with incoherent pump and single-particle losses. The study focuses on the quantum dynamics of particle imbalance and frequency-resolved spectral properties of the steady state, showing clear evidence of a localization-delocalization crossover. A finite pump-loss asymmetry restores a delocalization crossover in the imbalance and leads to finite intra-dimer dissipation.
NEW JOURNAL OF PHYSICS
(2021)
Article
Physics, Multidisciplinary
Shuta Nakajima, Nobuyuki Takei, Keita Sakuma, Yoshihito Kuno, Pasquale Marra, Yoshiro Takahashi
Summary: The influence of disorder on topological phenomena is significant, showing competition and interaction in experiments. Topologically protected charge transport, known as Thouless pumping, is achieved with disorder-dependent effects on the topological properties.
Article
Physics, Multidisciplinary
Koki Ono, Yugo Saito, Taiki Ishiyama, Toshiya Higomoto, Tetsushi Takano, Yosuke Takasu, Yasuhiro Yamamoto, Minoru Tanaka, Yoshiro Takahashi
Summary: The study measures isotope shifts for neutral Yb isotopes and constructs King plots, revealing nonlinearities and potential higher-order contributions in the measured isotope shifts. The analysis suggests the presence of at least two higher-order contributions and provides an upper limit for the product of couplings for a new boson, contributing to probing new physics through isotope-shift spectroscopy.
Article
Physics, Multidisciplinary
Ryui Kaneko, Ippei Danshita
Summary: This study utilizes tensor-network methods on classical computers to investigate the dynamics of the two-dimensional Bose-Hubbard model, comparing it to known limits and recent experiments. It also covers the intermediate region of moderate interactions.
COMMUNICATIONS PHYSICS
(2022)
Article
Physics, Multidisciplinary
Shintaro Taie, Eduardo Ibarra-Garcia-Padilla, Naoki Nishizawa, Yosuke Takasu, Yoshihito Kuno, Hao-Tian Wei, Richard T. Scalettar, Kaden R. A. Hazzard, Yoshiro Takahashi
Summary: In this study, a cold-atom simulator is used to realize a popular many-body model of quantum magnetism and achieve the record-coldest fermions. The experimental observations of spin correlations in a SU(6) Hubbard model confirm the enhancement of correlations due to strong Pomeranchuk cooling. The experimental data qualitatively agree with theoretical calculations, allowing the inference of the lowest achieved temperature for a cold-atom Fermi-Hubbard model.
Article
Physics, Multidisciplinary
Kantaro Honda, Shintaro Taie, Yosuke Takasu, Naoki Nishizawa, Masaya Nakagawa, Yoshiro Takahashi
Summary: We have observed the reversal of magnetic correlation from antiferromagnetic to ferromagnetic in a controlled manner by utilizing on-site twobody losses as a source of dissipation. We measured the dynamics of spin correlation in an isolated double-well optical lattice and observed a ferromagnetic spin correlation, consistent with the Dicke correlation expected in the long-time limit. This work demonstrates the control of quantum magnetism in open quantum systems with dissipation.
PHYSICAL REVIEW LETTERS
(2023)
Article
Optics
Mathias Mikkelsen, Ippei Danshita
Summary: It has been discovered that noise correlations measured by time-of-flight imaging in cold-atom experiments can probe the spin structure factor in the Mott-insulating regime of SU(2) Hubbard models. In this study, the mathematical relation between noise correlations and spin structure factor in the strong-interaction limit of SU(N) Hubbard models at any integer filling was derived. Numerical calculations based on the ground states of one-dimensional SU(N) Fermi-Hubbard models for 2≤N≤6 using the density-matrix renormalization-group method confirmed this relation in the regime of strong interactions. It was shown that the deviation between actual noise correlations and those obtained from the spin structure factor scaled as (t/U)^2 for rho = 1 at intermediate and large lattice sizes.
Article
Optics
Daichi Kagamihara, Ryui Kaneko, Shion Yamashika, Kota Sugiyama, Ryosuke Yoshii, Shunji Tsuchiya, Ippei Danshita
Summary: We investigate the time-dependent Renyi entanglement entropy after a quantum quench starting from the Mott-insulating and charge-density-wave states in a one-dimensional free boson system. The second Renyi entanglement entropy is found to be the negative of the logarithm of the permanent of a matrix consisting of timedependent single-particle correlation functions. From this relation and a permanent inequality, we obtain rigorous conditions for satisfying the volume-law entanglement growth. We also succeed in calculating the time evolution of the Renyi entanglement entropy in extremely large systems by brute-force computations of the permanent. We discuss possible applications of our findings to the real-time dynamics of noninteracting bosonic systems.
Article
Materials Science, Multidisciplinary
Shimpei Goto, Ryui Kaneko, Ippei Danshita
Summary: We investigate the sampling efficiency for simulating quantum many-body systems at finite temperatures using initial sampling states generated by applying Trotter gates to random phase product states (RPPSs). The number of Trotter gate applications is proportional to the system size, making the preparation easily achievable in fault-tolerant quantum computers. When the Trotter gates are made from a nonintegrable Hamiltonian, we observe an increase in sampling efficiency with system size, indicating that almost ideal sampling of initial states can be achieved in sufficiently large systems. We also find that the sampling efficiency is comparable to that obtained by a thermal pure quantum (TPQ) state method in some cases, suggesting that chaotic Hamiltonian dynamics can transform RPPSs into an alternative to TPQ states for evaluating thermal expectation values.
Article
Optics
Mathias Mikkelsen, Ryui Kaneko, Daichi Kagamihara, Ippei Danshita
Summary: The ground-state phase diagram of the one-dimensional attractive Fermi-Hubbard model with spin-dependent hoppings and an on-site Rabi coupling is investigated using the density matrix renormalization group method. It is shown that even in the limit of one component being immobile, the pair superfluidity can be resonantly enhanced when the Rabi coupling is on the order of the interaction strength just before the system starts to strongly polarize. An effective spin-1/2 XXZ model is derived to understand the ground-state properties in the strong attraction limit.
Article
Optics
Yoshihiro Machida, Ippei Danshita, Daisuke Yamamoto, Kenichi Kasamatsu
Summary: In this theoretical study, we investigate the dynamical formation of a self-bound quantum droplet in a two-component Bose-Hubbard system with an external trap potential. The behavior of the droplet can be induced by controlling the trap potential, and can be qualitatively described by an effective Ginzburg-Landau field theory.
Article
Physics, Multidisciplinary
Kazuma Nagao, Yosuke Takasu, Yoshiro Takahashi, Ippei Danshita
Summary: The study utilizes the SU(3) truncated Wigner approximation to analyze the far-from-equilibrium quantum dynamics of strongly interacting Bose gases in an optical lattice. Comparisons with exact computations show that both the SU(3) TWA and Gaussian approximation can quantitatively capture quantum dynamics on a specific timescale. However, noticeable deviations between theories and experiments indicate the need for proper consideration of the effects of spatial inhomogeneity.
PHYSICAL REVIEW RESEARCH
(2021)
Correction
Optics
Ippei Danshita, Daisuke Yamamoto, Yasuyuki Kato
Article
Materials Science, Multidisciplinary
Shimpei Goto, Ryui Kaneko, Ippei Danshita
Summary: A numerical method based on matrix product states was developed to simulate quantum many-body systems at finite temperatures without importance sampling. By adding Trotter gates to the RPPS approach, the sampling efficiency significantly increased and results were consistent with the purification approach. The method was able to simulate a frustrated spin-1/2 system where the purification approach failed.
Article
Physics, Multidisciplinary
Masaya Kunimi, Kazuma Nagao, Shimpei Goto, Ippei Danshita
Summary: By analyzing the dynamics of quantum spin systems, it is found that the validity timescale of DTWA increases algebraically with the range of the step function type interaction in both one- and two-dimensional systems.
PHYSICAL REVIEW RESEARCH
(2021)
