Article
Mechanics
Feng Pan, Yao-Zhong Zhang, Xiaohan Qi, Yue Liang, Yuqing Zhang, Jerry P. Draayer
Summary: The Bethe ansatz solution of the two-axis two-spin Hamiltonian is derived using the Jordan-Schwinger boson realization of the SU(2) algebra. The solution of the Bethe ansatz equations corresponds to zeros of the extended Heine-Stieltjes polynomials. Symmetry properties of excited levels and zeros of the polynomials are discussed, with a detailed study of the case of two equal spins showing symmetric levels and well-entangled excited states.
JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT
(2021)
Article
Mechanics
Milosz Panfil
Summary: This paper investigates the computation of dynamic correlation functions of quantum integrable models using the thermodynamic form-factor approach, focusing on local operators that conserve the number of particles and their two-particle-hole contributions. The method developed is applicable to any finite energy and entropy state, with a primary focus on thermal states. Additionally, the Lieb-Liniger model is used as an example to study the leading contribution from two-particle-hole excitations to the dynamic density-density correlation function, as well as contributions to two-point functions of higher local conserved densities and currents in integrable theories.
JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT
(2021)
Article
Physics, Multidisciplinary
Lachlan Bennett, Phillip S. Isaac, Jon Links
Summary: A recently proposed extended Bose-Hubbard model, which is a quantum integrable model, provides a theoretical framework for generating NOON states. By deriving a Bethe ansatz solution, exact asymptotic expressions for energies and eigenstates are obtained, and formulae for measurement probabilities and outcome fidelities are derived and benchmarked against numerical calculations.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2023)
Article
Mechanics
Jacopo De Nardis, Benjamin Doyon, Marko Medenjak, Milosz Panfil
Summary: This article reviews recent advances in exact results for dynamical correlation functions and related transport coefficients in interacting integrable models at large scales. The discussion includes topics such as Drude weights, conductivity and diffusion constants, as well as linear and nonlinear response in equilibrium and non-equilibrium states. The authors consider the problems from the perspectives of the general hydrodynamic theory of many-body systems and form-factor expansions in integrable models, showing how they provide a comprehensive and consistent set of exact methods for extracting large scale behaviors. Various applications in integrable spin chains and field theories are also discussed.
JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT
(2022)
Article
Physics, Multidisciplinary
Wen Li, Mert Okyay, Rafael Nepomechie
Summary: A probabilistic algorithm has been found for preparing Bethe eigenstates of the spin-1/2 Heisenberg spin chain on a quantum computer, but the success probability decreases exponentially with the chain length. Although it is feasible to compute antiferromagnetic ground-state spin-spin correlation functions for short chains, it is not possible for chains of moderate length.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2022)
Article
Physics, Particles & Fields
Xiang-Mao Ding, Tinglyer Zhang
Summary: This study extends previous research by demonstrating the one-to-one correspondence between supersymmetric vacua in three-dimensional N=2 gauge theories and the eigenstates of XXZ integrable spin chain Hamiltonians with open boundary conditions. The researchers explore the A2 quiver gauge theory and the sl3 open XXZ spin chain with diagonal boundary condition, and establish the correspondence between the vacuum equations of different gauge groups and Bethe Ansatz equations with different boundary parameters. Furthermore, they extend this research to the general Ar quiver gauge theory.
Article
Mechanics
Axel Cortes Cubero, Takato Yoshimura, Herbert Spohn
Summary: Our review covers the microscopic foundations of Generalized Hydrodynamics (GHD) through form factor expansions and the availability of a self-conserved current as two orthogonal approaches.
JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT
(2021)
Review
Physics, Multidisciplinary
Ana L. Retore
Summary: These lecture notes provide a pedagogical introduction to classical and quantum integrability, covering the construction and diagonalization of conserved charges in both classical and quantum integrable models.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2022)
Article
Mechanics
P. N. Bibikov
Summary: By using the quantum transfer matrix method, a perturbative expression for the free energy density of the Heisenberg-Ising chain with strong easy-axis anisotropy has been derived. The obtained result agrees with the direct high-temperature expansion as well as the low-temperature cluster expansion in the special subregime where quantum fluctuations are weak against thermodynamical ones.
JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT
(2022)
Article
Physics, Multidisciplinary
Ivan Lobaskin, Martin R. Evans, Kirone Mallick
Summary: This paper discusses the classification of one-dimensional exclusion processes with two species of particles that can be solved using a nested coordinate Bethe ansatz (BA). By applying the Yang-Baxter equations, the conditions for integrability of the underlying system are obtained. Three classes of integrable models are identified, with two of them being well-known in literature and the third one being recently studied, especially in the context of BA. The Bethe equations for this latter model and the associated dynamics encoding the large deviation of the currents are derived.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2023)
Article
Physics, Multidisciplinary
Jia-Feng Pan, Jia-Jia Luo, Xi-Wen Guan
Summary: By using an exact Bethe ansatz solution, this study rigorously investigates excitation spectra of the spin-1/2 Fermi gas, discovering different types of excitations such as particle-hole excitations and magnon excitations, and analyzing their properties in depth.
COMMUNICATIONS IN THEORETICAL PHYSICS
(2022)
Article
Mechanics
Sylvain Prolhac
Summary: The concept of integer counting processes is introduced, showing that the probability can be represented as a contour integral on a Riemann surface, defined by the characteristic equation of the generator. Several specific examples are discussed in the article.
JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT
(2022)
Article
Physics, Multidisciplinary
Frank Goehmann, Raphael Kleinemuehl, Alexander Weisse
Summary: The descriptive review of the fermionic basis approach to the theory of correlation functions of the XXZ quantum spin chain focuses on explicit formulae for short-range correlation functions that can be implemented on a computer. Within this approach, a class of stationary reduced density matrices, compatible with the integrable structure of the model, assumes a factorized form. Expectation values of local operators and two-point functions can be represented as multivariate polynomials in only two functions rho and omega and their derivatives with coefficients rational in the deformation parameter q.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2021)
Article
Physics, Particles & Fields
Nikolay Gromov, Nicolo Primi, Paul Ryan
Summary: In this paper, we study integrable SI(N) spin chains, which are not only exemplary quantum integrable systems but also have a wide range of applications. Using the Functional Separation of Variables (FSoV) technique and a new tool called Character Projection, we calculate all matrix elements of a complete set of operators, called principal operators, in the basis diagonalizing the conserved charges. We then derive determinant forms for the form-factors of multiple principal operators between arbitrary factorizable states, proving that the set of principal operators generates the complete spin chain Yangian. We also obtain the representation of these operators in the SoV bases, allowing the computation of correlation functions with any number of principal operators.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Article
Mechanics
Vincenzo Alba, Bruno Bertini, Maurizio Fagotti, Lorenzo Piroli, Paola Ruggiero
Summary: This paper provides a pedagogical introduction to the generalized hydrodynamic approach in inhomogeneous quenches in integrable many-body quantum systems, focusing on applications to bipartitioning protocols and trap quenches. Exact results for time-dependent correlation functions and entanglement evolution are discussed, as well as the theory's range of applicability, open questions, and future directions.
JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT
(2021)