Symmetry nonrestoration in a Gross-Neveu model with a random chemical potential
Symmetry nonrestoration in a Gross-Neveu model with a random chemical potential
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具有随机化学势的 Gross-Neveu 模型中的对称性不可恢复
DOI：
10.1103/physrevd.63.085014
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发表时间：
2000
影响因子：
5
通讯作者：
J. Kogut
中科院分区：
文献类型：
--
作者：
Seok;J. Kogut
我们研究了具有随机化学势的Gross-Neveu模型在三维和二维中的对称性行为。这相当于具有电荷共轭对称和手性对称的四费米子模型。在高温下，${Z}_{2}$手性对称总是恢复的。在三维中，无论无序强度的大小如何，初始自发破缺的电荷共轭对称性在高温下都不能恢复。在二维零温度下，随着无序强度的变化，电荷共轭对称性经历了从对称态（弱无序态）到破缺态（强无序态）的量子相变。对于任意无序强度值，电荷共轭对称的高温行为与零温行为相同。因此，在二维和强无序强度下，电荷共轭对称性在高温下不能恢复。
We study the symmetry behavior of the Gross-Neveu model in three and two dimensions with a random chemical potential. This is equivalent to a four-fermion model with charge conjugation symmetry as well as ${Z}_{2}$ chiral symmetry. At high temperature the ${Z}_{2}$ chiral symmetry is always restored. In three dimensions the initially spontaneously broken charge conjugation symmetry is not restored at high temperature, irrespective of the value of the disorder strength. In two dimensions and at zero temperature the charge conjugation symmetry undergoes a quantum phase transition from a symmetric state (for weak disorder) to a broken state (for strong disorder) as the disorder strength is varied. For any given value of disorder strength, the high-temperature behavior of the charge conjugation symmetry is the same as its zero-temperature behavior. Therefore, in two dimensions and for strong disorder strength the charge conjugation symmetry is not restored at high temperature.