论文标题
具有无限范围相互作用的量子时钟模型
Quantum clock models with infinite-range interactions
论文作者
论文摘要
我们以$ \ mathbb {z} _q $模型具有无限范围相互作用的类别研究，以零和有限温度研究相图。我们能够通过使用平均场方法和扰动膨胀来识别破坏对称性和琐碎阶段之间的过渡。我们对$ 2p $ body互动的哈密顿量进行分析，并找到任何$ p> 1 $的一阶过渡；在$ p = 1 $的情况下，过渡是$ q = 3 $的一阶，否则是二阶。在无限范围的情况下，没有无间隙的不相差相的痕迹，但是当横向场是最大手性的时，该模型是任意较大场的对称性阶段。我们分析以无限$ q $的极限研究transtion，该模型具有连续的$ u（1）$对称性。
We study the phase diagram, both at zero and finite temperature, in a class of $\mathbb{Z}_q$ models with infinite range interactions. We are able to identify the transitions between a symmetry-breaking and a trivial phase by using a mean-field approach and a perturbative expansion. We perform our analysis on a Hamiltonian with $2p$-body interactions and we find first-order transitions for any $p>1$; in the case $p=1$, the transitions are first-order for $q=3$ and second-order otherwise. In the infinite-range case there is no trace of gapless incommensurate phase but, when the transverse field is maximally chiral, the model is in a symmetry-breaking phase for arbitrarily large fields. We analytically study the transtion in the limit of infinite $q$, where the model possesses a continuous $U(1)$ symmetry.
