# Thermodynamics of the Spin-1/2 Antiferromagnetic Uniform Heisenberg Chain

## Abstract

We present a new application of the traditional thermodynamic Bethe ansatz to the spin-1/2 antiferromagnetic uniform Heisenberg chain and derive exact nonlinear integral equations for just two functions describing the elementary excitations. By using this approach, the magnetic susceptibility {chi} and specific heat C versus temperature T are calculated to high accuracy for 5x10{sup -25}{<=}T/J{<=}5 . The {chi}(T) data agree very well at low T with the asymptotically exact theoretical low-T prediction of Lukyanov [Nucl. Phys. B522, 533 (1998)]. The unknown coefficients of the second and third lowest-order logarithmic correction terms in Lukyanov's theory for C(T) are estimated from the C(T) data. (c) 2000 The American Physical Society.

- Authors:

- Institut fuer Theoretische Physik, Universitaet zu Koeln, Zuelpicher Strasse 77, 50937 Koeln, (Germany)
- (Germany)
- Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011 (United States)

- Publication Date:

- OSTI Identifier:
- 20216596

- Resource Type:
- Journal Article

- Journal Name:
- Physical Review Letters

- Additional Journal Information:
- Journal Volume: 84; Journal Issue: 20; Other Information: PBD: 15 May 2000; Journal ID: ISSN 0031-9007

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; HEISENBERG MODEL; ANTIFERROMAGNETISM; THERMODYNAMIC PROPERTIES; CHAINS; INTEGRAL EQUATIONS; MAGNETIC SUSCEPTIBILITY; SPECIFIC HEAT; THEORETICAL DATA

### Citation Formats

```
Kluemper, A., Fachbereich Physik, Universitaet Dortmund, 44221 Dortmund,, and Johnston, D. C.
```*Thermodynamics of the Spin-1/2 Antiferromagnetic Uniform Heisenberg Chain*. United States: N. p., 2000.
Web. doi:10.1103/PhysRevLett.84.4701.

```
Kluemper, A., Fachbereich Physik, Universitaet Dortmund, 44221 Dortmund,, & Johnston, D. C.
```*Thermodynamics of the Spin-1/2 Antiferromagnetic Uniform Heisenberg Chain*. United States. doi:10.1103/PhysRevLett.84.4701.

```
Kluemper, A., Fachbereich Physik, Universitaet Dortmund, 44221 Dortmund,, and Johnston, D. C. Mon .
"Thermodynamics of the Spin-1/2 Antiferromagnetic Uniform Heisenberg Chain". United States. doi:10.1103/PhysRevLett.84.4701.
```

```
@article{osti_20216596,
```

title = {Thermodynamics of the Spin-1/2 Antiferromagnetic Uniform Heisenberg Chain},

author = {Kluemper, A. and Fachbereich Physik, Universitaet Dortmund, 44221 Dortmund, and Johnston, D. C.},

abstractNote = {We present a new application of the traditional thermodynamic Bethe ansatz to the spin-1/2 antiferromagnetic uniform Heisenberg chain and derive exact nonlinear integral equations for just two functions describing the elementary excitations. By using this approach, the magnetic susceptibility {chi} and specific heat C versus temperature T are calculated to high accuracy for 5x10{sup -25}{<=}T/J{<=}5 . The {chi}(T) data agree very well at low T with the asymptotically exact theoretical low-T prediction of Lukyanov [Nucl. Phys. B522, 533 (1998)]. The unknown coefficients of the second and third lowest-order logarithmic correction terms in Lukyanov's theory for C(T) are estimated from the C(T) data. (c) 2000 The American Physical Society.},

doi = {10.1103/PhysRevLett.84.4701},

journal = {Physical Review Letters},

issn = {0031-9007},

number = 20,

volume = 84,

place = {United States},

year = {2000},

month = {5}

}