Related papers: Spin Drude weight for the integrable XXZ chain wit…
Bethe Ansatz solutions of the open spin-1/2 integrable XXZ quantum spin chain at roots of unity with nondiagonal boundary terms containing two free boundary parameters have recently been proposed. We use these solutions to compute the…
Thermodynamics provides a transparent definition of the free energy of density functional theory (DFT), and of its derivatives - the potentials, at finite temperatures T. By taking the T to 0 limit, it is shown here that both DFT and…
The spin-1/2 Ising-Heisenberg tetrahedral chain is exactly solved using its local gauge symmetry, which enables one to establish a rigorous mapping with the corresponding chain of composite Ising spins tractable within the transfer-matrix…
An exact description of integrable spin chains at finite temperature is provided using an elementary algebraic approach in the complete Hilbert space of the system. We focus on spin chain models that admit a description in terms of free…
A Bethe Ansatz solution of the open spin-1/2 XXZ quantum spin chain with nondiagonal boundary terms has recently been proposed. Using a numerical procedure developed by McCoy et al., we find significant evidence that this solution can yield…
On the basis of Bethe ansatz solution of one dimensional Kondo model with electronic interaction, the thermodynamics equilibrium of the system in finite temperature is studied in terms of the strategy of Yang and Yang. The string hypothesis…
This thesis contains two results for the low temperature behavior of quantum spin systems. First, we present a lower bound for the spin-1 XXZ chain in finite volumes in terms of the gap of the two-site Hamiltonian. The estimate is derived…
To clarify the transport property mediated by bound magnons in a spin nematic state, we investigate the spin Drude weight of a spin-1/2 $J_{1}$-$J_{2}$ Heisenberg chain with ferromagnetic $J_{1}$ and antiferromagnetic $J_{2}$ in a magnetic…
We solve in closed form the simplest (su(1|1)) supersymmetric version of Inozemtsev's elliptic spin chain, as well as its infinite (hyperbolic) counterpart. The solution relies on the equivalence of these models to a system of free spinless…
Finite-temperature properties of the frustrated Hubbard model are theoretically examined by using the recently proposed thermal pure quantum state, which is an unbiased numerical method for finite-temperature calculations. By performing…
The anomalous thermal conductivity in spin chains observed in experiments is studied for the low temperature regime. In the effective dynamics with most realistic perturbations, the so-called Umklapp terms is irrelevant to reduce mean free…
We consider a two-parameter $(\bar c, \tilde c)$ family of quantum integrable Hamiltonians for a chain of alternating spins of spin $s=1/2$ and $s=1$. We determine the thermodynamics for low-temperature $T$ and small external magnetic field…
Owing to the fact that the particle current operator in non-relativistic gases is proportional to the total momentum operator, the particle transport in such systems is always ballistic and fully characterized by a Drude weight $\Delta$.…
By means of inelastic neutron scattering we investigate finite temperature dynamics in the quantum spin ladder compound (C$_5$H$_{12}$N)$_2$CuBr$_4$ (BPCB) near the magnetic field induced quantum critical point with dynamical exponent…
Integrable quantum spin chains display distinctive physical properties making them a laboratory to test and assess different states of matter. The study of the finite temperature properties is possible by use of the thermodynamic Bethe…
We represent the density matrix of a finite segment of the integrable isotropic spin-1 chain in the thermodynamic limit as a multiple integral. Our integral formula is valid at finite temperature and also includes a homogeneous magnetic…
The transfer matrix of the general integrable open XXZ quantum spin chain obeys certain functional relations at roots of unity. By exploiting these functional relations, we determine the Bethe Ansatz solution for the transfer matrix…
Combining a lattice path integral formulation for thermodynamics with the solution of the quantum inverse scattering problem for local spin operators, we derive a multiple integral representation for the time-dependent longitudinal…
We derive the fusion hierarchy of functional equations for critical A-D-E lattice models related to, the sl(2) unitary minimal models, the parafermionic models and the supersymmetric models of conformal field theory, and deduce the related…
Transition rates and dynamic spin structure factor at zero temperature for the spin-1/2 XXZ chain at critical regime in a magnetic field are numerically evaluated in terms of the exact determinant representations for the form factors and…