scholarly journals T − W relation and free energy of the Heisenberg chain at a finite temperature

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Pengcheng Lu ◽  
Yi Qiao ◽  
Junpeng Cao ◽  
Wen-Li Yang ◽  
Kang jie Shi ◽  
...  
Keyword(s):  
Free Energy ◽  
Spin Chain ◽  
Quantum Spin ◽  
Heisenberg Chain ◽  
Quantum Spin Chain ◽  
Heisenberg Spin ◽  
Heisenberg Spin Chain ◽  
Lattice Quantum ◽  
Quantum Integrable Models ◽  
Invariant Quantum

Abstract A new nonlinear integral equation (NLIE) describing the thermodynamics of the Heisenberg spin chain is derived based on the t − W relation of the quantum transfer matrices. The free energy of the system in a magnetic field is thus obtained by solving the NLIE. This method can be generalized to other lattice quantum integrable models. Taking the SU(3)-invariant quantum spin chain as an example, we construct the corre- sponding NLIEs and compute the free energy. The present results coincide exactly with those obtained via other methods previously.

scholarly journals Quantum spin transistor with a Heisenberg spin chain

2016 ◽  
Vol 7 (1) ◽  
Author(s):  
O. V. Marchukov ◽  
A. G. Volosniev ◽  
M. Valiente ◽  
D. Petrosyan ◽  
N. T. Zinner
Keyword(s):  
Spin Chain ◽  
Quantum Spin ◽  
Heisenberg Spin ◽  
Heisenberg Spin Chain ◽  
Spin Transistor

Thermodynamics of the Isotropic Heisenberg Quantum Spin Chain

2019 ◽  
pp. 641-654
Author(s):  
Hans-Peter Eckle
Keyword(s):  
Free Energy ◽  
Bethe Ansatz ◽  
Finite Temperature ◽  
Spin Chain ◽  
Conformal Symmetry ◽  
Quantum Spin ◽  
Quantum Spin Chain ◽  
Explicit Formulas ◽  
Thermodynamic Bethe Ansatz ◽  
Physical Quantities

This chapter presents the extension of the Bethe ansatz to finite temperature, the thermodynamic Bethe ansatz, for the antiferromagnetic isotropic Heisenberg quantum spin chain, the XXX quantum spin chain. It discusses how the added complications of this model arise from the more complicated structure of excitations of the quantum spin chain, the complex string excitations, which have to be included in the Bethe ansatz thermodynamics. It derives the integral equations of the thermodynamic Bethe ansatz for the XXX quantum spin chain and mentions explicit formulas for the free energy of the quantum spin chain and some interesting physical quantities, especially making contact with predictions of conformal symmetry.

scholarly journals Stochastic dissipative quantum spin chains (I) : Quantum fluctuating discrete hydrodynamics

2017 ◽  
Vol 3 (5) ◽  
Author(s):  
Michel Bauer ◽  
Denis Bernard ◽  
Tony Jin
Keyword(s):  
Spin Chain ◽  
Quantum Dynamics ◽  
Quantum Noise ◽  
Quantum Spin ◽  
Spin Chains ◽  
Quantum Spin Chains ◽  
Heisenberg Spin ◽  
Heisenberg Spin Chain ◽  
Dissipative Effects ◽  
Macroscopic Fluctuation Theory

Motivated by the search for a quantum analogue of the macroscopic fluctuation theory, we study quantum spin chains dissipatively coupled to quantum noise. The dynamical processes are encoded in quantum stochastic differential equations. They induce dissipative friction on the spin chain currents. We show that, as the friction becomes stronger, the noise induced dissipative effects localize the spin chain states on a slow mode manifold, and we determine the effective stochastic quantum dynamics of these slow modes. We illustrate this approach by studying the quantum stochastic Heisenberg spin chain.

scholarly journals SCALAR KINKS

1994 ◽  
Vol 08 (25n26) ◽  
pp. 3473-3485 ◽  
Author(s):  
H.J. DE VEGA ◽  
LUCA MEZINCESCU ◽  
RAFAEL I. NEPOMECHIE
Keyword(s):  
Spin Chain ◽  
Quantum Spin ◽  
Heisenberg Chain ◽  
Quantum Spin Chain ◽  
S Matrix ◽  
Scalar Scattering

We determine the excitations and S matrix of an integrable isotropic antiferromagnetic quantum spin chain of alternating spin 1/2 and spin 1. There are two types of gapless one-particle excitations: the usual spin 1/2 (“spinor”) kink, and a new spin 0 (“scalar”) kink. Remarkably, the scalar-spinor scattering is nontrivial, yet the spinor-spinor scattering is the same as for the Heisenberg chain. Moreover, there is no scalar-scalar scattering.

scholarly journals Heisenberg spin chain as a worldsheet coordinate for lightcone quantized string

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Charles B. Thorn
Keyword(s):  
Energy Spectrum ◽  
Excited States ◽  
Spin Chain ◽  
Discrete Dynamical System ◽  
Heisenberg Spin ◽  
Free Fermions ◽  
Heisenberg Spin Chain ◽  
Delta Sigma ◽  
Special Cases ◽  
Quantized String

Abstract Although the energy spectrum of the Heisenberg spin chain on a circle defined by$$ H=\frac{1}{4}\sum \limits_{k=1}^M\left({\sigma}_k^x{\sigma}_{k+1}^x+{\sigma}_k^y{\sigma}_{k+1}^y+\Delta {\sigma}_k^z{\sigma}_{k+1}^z\right) $$ H = 1 4 ∑ k = 1 M σ k x σ k + 1 x + σ k y σ k + 1 y + Δ σ k z σ k + 1 z is well known for any fixed M, the boundary conditions vary according to whether M ∈ 4ℕ + r, where r = −1, 0, 1, 2, and also according to the parity of the number of overturned spins in the state, In string theory all these cases must be allowed because interactions involve a string with M spins breaking into strings with M1< M and M − M1 spins (or vice versa). We organize the energy spectrum and degeneracies of H in the case ∆ = 0 where the system is equivalent to a system of free fermions. In spite of the multiplicity of special cases, in the limit M → ∞ the spectrum is that of a free compactified worldsheet field. Such a field can be interpreted as a compact transverse string coordinate x(σ) ≡ x(σ) + R0. We construct the bosonization formulas explicitly in all separate cases, and for each sector give the Virasoro conformal generators in both fermionic and bosonic formulations. Furthermore from calculations in the literature for selected classes of excited states, there is strong evidence that the only change for ∆ ≠ 0 is a change in the compactification radius R0→ R∆. As ∆ → −1 this radius goes to infinity, giving a concrete example of noncompact space emerging from a discrete dynamical system. Finally we apply our work to construct the three string vertex implied by a string whose bosonic coordinates emerge from this mechanism.

scholarly journals Magnetic properties of theS= ½ Heisenberg spin-chain material (6MAP)CuCl3

2009 ◽  
Vol 150 (4) ◽  
pp. 042159 ◽  
Author(s):  
M Ozerov ◽  
E Čižmár ◽  
J Wosnitza ◽  
S A Zvyagin ◽  
F Xiao ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Spin Chain ◽  
Heisenberg Spin ◽  
Heisenberg Spin Chain
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