Article
Materials Science, Multidisciplinary
Natalia Chepiga, Ian Affleck, Frederic Mila
Summary: This study investigates the properties of a frustrated spin-5/2 chain with next-nearest-neighbor two- and three-site interactions, revealing the nature of the transition into the dimerized phase and the presence of a critical floating phase at intermediate values of the next-nearest-neighbor interaction. The research provides evidence for the nature of the phase transitions and the dimerization process induced by the interactions, with implications discussed for the iron oxide Bi3FeMo2O12.
Article
Physics, Multidisciplinary
Luciano Loris Viteritti, Riccardo Rende, Federico Becca
Summary: The ViT architecture, which utilizes the self-attention mechanism to capture long-range correlations, has become the leading model for natural language processing and computer vision tasks. We propose an adaptation of this architecture, called ViT wave function, with complex parameters for variational neural-network states of quantum many-body systems. Applying this idea to the one-dimensional J1-J2 Heisenberg model, we demonstrate that a relatively simple parametrization achieves excellent results for both gapped and gapless phases.
PHYSICAL REVIEW LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Ren-Gui Zhu
Summary: The study investigates the ground state energy and low-energy excitation of the frustrated ferromagnetic chain model in its incommensurate singlet phase using linear spin wave theory (LSWT). By diagonalizing the bosonic Hamiltonian and obtaining the spin wave spectrum analytically, a new way to determine the critical point between the ferromagnetic phase and the incommensurate singlet phase is proposed. Quantum corrections to the classical ground state energy show minimal spin fluctuations near the critical point.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2021)
Article
Physics, Multidisciplinary
Xiaojian Bai, Shang-Shun Zhang, Zhiling Dun, Hao Zhang, Qing Huang, Haidong Zhou, Matthew B. Stone, Alexander Kolesnikov, Feng Ye, Cristian D. Batista, Martin Mourigal
Summary: Neutron-scattering measurements on FeI2 reveal a dispersive band of mixed dipolar-quadrupolar fluctuations just above its ground state, an exotic magnetic excitation without a classical counterpart. This excitation arises from anisotropic exchange interactions that hybridize overlapping modes carrying fundamentally different quantum numbers. Our work highlights the possibility of quantum excitations without classical counterparts even in the presence of fully developed magnetic order.
Article
Materials Science, Multidisciplinary
Toru Sakai, Ryosuke Nakanishi, Takaharu Yamada, Rito Furuchi, Hiroki Nakano, Hirono Kaneyasu, Kiyomi Okamoto, Takashi Tonegawa
Summary: The behavior of the S = 1/2 quantum spin ladder system with anisotropic ferromagnetic exchange interaction under magnetic field is investigated using numerical diagonalization and density matrix renormalization group (DMRG) analyses. It is found that a nematic-spin-correlation-dominant Tomonaga-Luttinger liquid (TLL) phase appears in certain high magnetic fields, where a two-magnon bound state is realized. A field-induced phase transition from the two-magnon-bound TLL phase to the single-magnon TLL phase is observed for suitable parameters, followed by a re-entrant transition back to the two-magnon-bound TLL phase. Several phase diagrams on the coupling anisotropy-magnetization-magnetic field plane are presented. The results propose a candidate system exhibiting the spin nematic phase without biquadratic interaction or frustration.
Article
Materials Science, Multidisciplinary
O. A. Moreno Segura, K. Hallberg, A. A. Aligia
Summary: This study calculates the charge and spin gaps in the ionic Hubbard chain, considering density-dependent hopping with electron-hole symmetry. The disappearance of the charge (spin) gap indicates a quantum critical point in the charge (spin) sector. Between these critical points, the system behaves as a fully gapped spontaneously dimerized insulator. The study focuses on this region and explores the possibility of an adiabatic Thouless pump with alternating hopping, limited by the size of the gaps.
Article
Materials Science, Multidisciplinary
Yi Hu, Patrick Charbonneau
Summary: The paper discusses the use of the exact numerical transfer matrix (TM) method to study Ising models with frustrated next-nearest-neighbor interactions. By extending the method to various frustrated models, high-accuracy TM numerics help clarify physical ambiguities and provide a clearer overview of phase formation in two dimensions.
Article
Materials Science, Multidisciplinary
Hiroshi Funaki, Ai Yamakage, Mamoru Matsuo
Summary: We develop a microscopic theory of tunneling spin transport at the magnetic interface between a ferromagnetic insulator (FI) and a ferromagnetic superconductor (FSC) driven by ferromagnetic resonance. The spin susceptibilities of the FSC can be extracted from the spin currents by tuning the easy axis of the FI, providing a probe for the symmetries of the spin-triplet Cooper pairing. This research offers potential for utilizing the combination of magnetism and superconductivity in spin devices.
Article
Physics, Multidisciplinary
H. Zahir, A. Hasnaoui, R. Aharrouch, M. Madani, A. Lafhal, N. Hachem, M. El Bouziani
Summary: The study utilized the real-space Migdal-Kadanoff renormalization group technique to examine the mixed spin Blume-Capel model on a d-dimensional hypercubic lattice. It identified a critical dimension around 2.05, leading to different phase diagram topologies above and below this threshold. The analysis indicates the absence of a tricritical point and highlights the presence of two first-order transitions at very low temperatures.
INTERNATIONAL JOURNAL OF THEORETICAL PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Hiroki Hanate, Daigorou Hirai, Zenji Hiroi, Kazuyuki Matsuhira
Summary: We investigated the magnetic properties of single-crystal Ca5Ir3O12 with a hexagonal noncentrosymmetric structure. The magnetic phase transition temperature was found to be affected by the direction of an applied magnetic field, indicating the possible presence of multipole magnetic ordering.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
F. Landolt, Z. Yan, S. Gvasaliya, K. Beauvois, E. Ressouche, J. Xu, A. Zheludev
Summary: Single crystals of the frustrated S = 1/2 ferro-antiferromagnetic proximate square lattice material SrZnVO(PO4)2 were studied in various experiments, revealing magnetic frustration and quantum renormalization of exchange constants. A novel presaturation phase was observed in the H-T magnetic phase diagram, showing similarities and differences with a previously studied compound.
Article
Physics, Multidisciplinary
E. M. Jalal, A. Hasnaoui, A. El Kenz, N. Hachem, H. Saadi, S. Zouhair, M. El Bouziani
Summary: This study investigates the phase diagrams of the spin-1 Ising model with a random crystal field on two- and three-dimensional lattices using renormalization group theory. The random crystal field follows a general two pics distribution, and when p = 0.5, characteristic phenomena such as the dependence of the tricritical point on the disorder of the crystal field are observed. The first-order transition is destroyed for all values of the crystal field Delta when alpha >= 0.7 for d = 2 and alpha >= 0.93 for d = 3. Additionally, a reentrant behavior may occur in the system under certain conditions of alpha in the delta = 3 case. A comparison with recent works on the Blume-Capel model with random crystal field is discussed.
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
(2023)
Article
Physics, Multidisciplinary
Anaelle Legros, Shang-Shun Zhang, Xiaojian Bai, Hao Zhang, Zhiling Dun, W. Adam Phelan, Cristian D. Batista, Martin Mourigal, N. P. Armitage
Summary: In this study, a wealth of multimagnon bound states were observed in the strongly anisotropic spin-1 triangular antiferromagnet FeI2 using time-domain terahertz spectroscopy. These unconventional excitations can alter the properties of ordered magnets due to attractive magnon-magnon interactions. By analyzing the energy-magnetic field spectrum using an exact diagonalization method, up to 4- and 6-magnon bound states hybridized with single magnons were detected, providing a unique platform to study decay and renormalization similar to few-body problems found in cold-atom, nuclear, and particle physics.
PHYSICAL REVIEW LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Sambunath Das, Dayasindhu Dey, Manoranjan Kumar, S. Ramasesha
Summary: The study of quantum phases in a spin-1 skewed ladder system reveals four distinct phases, namely the AF phase, the ferrimagnetic phase with different spin configurations, and a reentrant nonmagnetic phase. The system also shows the presence of spin current at specific J(1) values due to breaking of symmetries.
Article
Materials Science, Multidisciplinary
Dmytro Tarasevych, Andreas Rueckriegel, Savio Keupert, Vasilios Mitsiioannou, Peter Kopietz
Summary: Using the functional renormalization group approach, we investigated the phase diagram of a frustrated quantum spin system and found that considering dynamic spin fluctuations and the renormalization of the four-spin interaction can estimate critical temperatures accurately.
Review
Physics, Multidisciplinary
B. Bertini, F. Heidrich-Meisner, C. Karrasch, T. Prosen, R. Steinigeweg, M. Znidaric
Summary: Significant progress has been made in the theoretical understanding of transport properties in one-dimensional quantum lattice systems in the past decade, with Bethe-ansatz integrable models and novel simulation methods playing important roles. The discovery of quasilocal conserved quantities provides insight into the origins of finite-temperature transport behavior, while state-of-the-art theoretical methods, including matrix-product-state-based simulation and generalized hydrodynamics, are discussed. The close connection between theoretical models and recent experiments, particularly in the context of quantum magnets and ultracold quantum gases in optical lattices, is also highlighted.
REVIEWS OF MODERN PHYSICS
(2021)
Article
Nanoscience & Nanotechnology
T. Zavertanyi, A. Kolezhuk
Summary: This study investigates antiferromagnetic systems with enhanced nearly-SU(N) symmetry, focusing on cases where N=3 and N=4. Near the SU(N) point, the low-energy physics of the system can be described by the CPN-1 model with an additional symmetry-breaking term. Analysis shows that these systems exhibit a peculiar effect of topological binding.
Article
Computer Science, Interdisciplinary Applications
Jan Stolpp, Thomas Kohler, Salvatore R. Manmana, Eric Jeckelmann, Fabian Heidrich-Meisner, Sebastian Paeckel
Summary: Studying lattice models consisting of high-dimensional local degrees of freedom without global particle-number conservation is an important problem class in the field of strongly correlated quantum many body systems. These systems can't be analytically treated and require numerical methods, with matrix-product states serving as a flexible and generic ansatz class. Tailored methods are needed to truncate the dimension for efficient simulations.
COMPUTER PHYSICS COMMUNICATIONS
(2021)
Article
Chemistry, Physical
M. ten Brink, S. Graeber, M. Hopjan, D. Jansen, J. Stolpp, F. Heidrich-Meisner, P. E. Bloechl
Summary: In this study, we benchmarked several quantum-chemistry methods against exact quantum-many-body techniques by studying real-time dynamics in the Holstein model. We found that the multitrajectory Ehrenfest method accurately captures ultrashort time dynamics, while the surface-hopping method with corrections provides a better description of long-time behavior. The multiconfigurational Ehrenfest method is a significant improvement over the multitrajectory Ehrenfest method in small systems, but convergence is slower for extended systems. We also showed that DMRG-LBO is a useful tool for evaluating the quality of quantum-chemistry methods.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Ceren B. Dag, Philipp Uhrich, Yidan Wang, Ian P. McCulloch, Jad C. Halimeh
Summary: Recently, the usefulness of single-site observables in probing critical slowing down in sudden quench dynamics has been demonstrated. In this study, we show the potential of single-site magnetization as a probe of quantum phase transitions in integrable and nonintegrable transverse-field Ising chains (TFIC). We prove analytically the requirement of zero modes for the emergence of a quasi-stationary regime near the edge of the probe site, and demonstrate how this regime leads to nonanalytic behavior in the dynamical order profiles. Our t-DMRG calculations confirm the predictions of the quench mean-field theory for near-integrable TFIC through finite-size and finite-time scaling analyses. We find that both finite-size and finite-time analyses suggest the existence of a dynamical critical point for a strongly nonintegrable and locally connected TFIC. Finally, we observe the presence of a quasi-stationary regime in the power-law interacting TFIC and extract local dynamical order profiles for TFIC in the long-range Ising universality class with algebraic light cones.
Article
Materials Science, Multidisciplinary
Ming-Chiang Chung, Guang-Yu Huang, Ian P. McCulloch, Yuan-Hong Tsai
Summary: Using machine learning, the study investigates quantum phase transitions of magnetism systems and successfully maps out accurate phase diagrams and boundaries. The use of relevant correlation functions helps distinguish different phases and the analysis of silhouette values indicates a strong positive correlation near phase transition points.
Article
Materials Science, Multidisciplinary
Suman Mondal, Eric Bertok, Fabian Heidrich-Meisner
Summary: The study focuses on the topological Thouless pumping in many-body systems where charge carriers interact with local optical phonons. The quantized charge transport breaks down in the presence of phonons, and there can be non-quantized negative and positive charge transport. The modified effective pumping path due to electron-phonon coupling accurately explains the underlying physics.
Article
Quantum Science & Technology
Jad C. Halimeh, Ian P. McCulloch, Bing Yang, Philipp Hauke
Summary: The study of the topological 0-angle in gauge theories is of great significance for understanding phenomena such as violations of charge-parity symmetry, topological transitions, and confinement-deconfinement transitions. This research demonstrates the feasibility of adding a tunable topological 0-term to a theory with U(1) gauge symmetry and shows the observed effects of this term. The work opens up new possibilities for studying topological gauge-theory terms in large-scale cold-atom quantum simulators.
Article
Materials Science, Multidisciplinary
E. Bertok, F. Heidrich-Meisner, A. A. Aligia
Summary: The study focuses on splitting a critical point into two separate critical points by adding a Hubbard interaction and extending it to a spinful Rice-Mele model. The research investigates the charge and spin transport between two systems in various scenarios, including adding staggered magnetic fields or Ising-type spin couplings.
Article
Physics, Multidisciplinary
Tomohiro Hashizume, Ian P. McCulloch, Jad C. Halimeh
Summary: In this study, we investigate two separate notions of dynamical phase transitions in the two-dimensional nearest-neighbor transverse-field Ising model. Our numerical results suggest that quenches below the dynamical critical point result in a ferromagnetic long-time steady state, while quenches above the dynamical critical point lead to a paramagnetic long-time steady state. Quenches slightly above the dynamical critical point exhibit a coexistence region.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Materials Science, Multidisciplinary
Miroslav Hopjan, Giuliano Orso, Fabian Heidrich-Meisner
Summary: This study investigates the delocalization transition in closed quantum systems with a many-body localized phase using a quantitative measure for Fock-space localization. The scaling behavior across delocalization transitions is systematically studied, and critical points are identified from scaling collapses of numerical data. Different scaling behavior is observed for interacting fermions with random disorder, indicative of a Kosterlitz-Thouless transition.
Article
Materials Science, Multidisciplinary
David Jansen, Christian Jooss, Fabian Heidrich-Meisner
Summary: This study uses the density-matrix renormalization group method to investigate the half-filled Holstein model with a linear potential, observing a decay of charge density wave states under strong potential strength. Local basis optimization selects important linear combinations of local oscillator states, termed optimal modes, showing the necessity for many of these modes to capture the decay dynamics. Additionally, the current through the structure in the metallic regime is computed as a function of voltage, highlighting the increasing significance of electron-phonon coupling strengths with higher voltages.
Article
Materials Science, Multidisciplinary
Miroslav Hopjan, Fabian Heidrich-Meisner, Vincenzo Alba
Summary: The study investigates a spatial subsystem entropy extracted from the one-particle density matrix (OPDM) of one-dimensional disordered interacting fermions that host a many-body localized (MBL) phase. The OPDM entropy exhibits scaling features of localization even though it is only an upper bound to the von Neumann entropy. The OPDM entropy follows an area law in eigenstates and grows logarithmically with time after a quantum quench, with these features surviving even at moderately large interactions and towards the transition into the ergodic phase.
Article
Materials Science, Multidisciplinary
Christoph Schoenle, David Jansen, Fabian Heidrich-Meisner, Lev Vidmar
Summary: The study investigates a quantum chaotic spin-fermion model in a one-dimensional lattice, analyzing translationally invariant observables related to transport properties and connecting them with the ETH. Results show that current matrix elements exhibit a system-size dependence different from other observables, with other observables displaying a Drude-like structure with Lorentzian frequency dependence.
Article
Optics
A. L. C. Hayward, E. Bertok, U. Schneider, F. Heidrich-Meisner
Summary: Recent experiments have shown integer-quantized topological charge pumping in ultracold quantum gases, motivating a study on the effects of static disorder on topological Thouless charge pumping. The study found that the space-integrated local Chern marker is best for quantitatively determining topological transitions in disordered systems, and observed a disorder-driven breakdown of the quantized charge pump. The analysis suggests that the stability of quantized pumping may be overestimated by the disorder average of the bulk gap, with the typical value of energy gap distribution providing a better estimate.
