Thermodynamics of integrable chains with alternating spins.
Thermodynamics of integrable chains with alternating spins.
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DOI：
10.1103/physrevb.49.13223
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发表时间：
1993-03
期刊：
影响因子：
--
通讯作者：
de Vega HJ;Mezincescu;Nepomechie
中科院分区：
文献类型：
--
作者：
de Vega HJ;Mezincescu;Nepomechie
考虑自旋为s=1/2和s=1的交替自旋链的双参数量子可积哈密顿量族（\bar c，\tilde c）.我们确定了低温T和小外磁场H的热力学性质，在T 0，c > 0）的情况下，模型有两个无隙激发.特别地，对于$\bar c = \tilde c$，该模型是共形不变的，并且具有中心电荷$c_{vir} = 2$。当这些参数之一为零时，Bethe Answer方程允许无穷多个具有最低能量的解。
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 $H$, with $T 0, \tilde c > 0)$ case, the model has two gapless excitations. In particular, for $\bar c = \tilde c$, the model is conformally invariant and has central charge $c_{vir} = 2$. When one of these parameters is zero, the Bethe Ansatz equations admit an infinite number of solutions with lowest energy.