Klumper A, Johnston DC
Institut fur Theoretische Physik, Universitat zu Koln, Zulpicher Strasse 77, 50937 Koln, Germany and Fachbereich Physik, Universitat Dortmund, 44221 Dortmund, Germany.
Phys Rev Lett. 2000 May 15;84(20):4701-4. doi: 10.1103/PhysRevLett.84.4701.
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(-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.
我们展示了传统热力学贝塞耳假设在自旋-1/2反铁磁均匀海森堡链上的一种新应用，并推导出了仅描述基本激发的两个函数的精确非线性积分方程。通过使用这种方法，对于5×10⁻²⁵≤T/J≤5的情况，高精度地计算了磁化率χ和比热容C与温度T的关系。χ(T)数据在低温下与卢基扬诺夫[《核物理B》522, 533 (1998)]的渐近精确理论低温预测非常吻合。根据C(T)数据估计了卢基扬诺夫理论中C(T)的第二和第三低阶对数修正项的未知系数。
