Deconfined Critical Point in a Doped Random Quantum Heisenberg Magnet
Deconfined Critical Point in a Doped Random Quantum Heisenberg Magnet
复制标题
DOI：
10.1103/physrevx.10.021033
复制
发表时间：
2020-05-12
影响因子：
12.5
通讯作者：
Sachdev, Subir
中科院分区：
文献类型：
--
作者：
Joshi, Darshan G.;Li, Chenyuan;Sachdev, Subir
我们描述了一个完全连接的晶格上的电子的相图与随机跳跃，受随机海森堡自旋交换相互作用之间的任何一对网站和限制，没有双重占用。微扰重整化群分析产生一个临界点，在非零临界值p（c）的空穴掺杂p远离半填充绝缘体的分数激发。我们计算两个循环的重整化群，但得到了所有循环阶的一些指数。我们认为临界点p（c）的两侧是限制相：当p > p（c）时载流子密度为1 + p的无序费米液体和当p < p（c）时载流子密度为p的金属自旋玻璃。临界行为的额外证据是从一个模型的大M分析中获得的，该模型将SU（2）自旋对称性扩展到SU（M）。我们讨论的关系，这解除量子临界点附近的铜酸盐现象学的关键方面。
We describe the phase diagram of electrons on a fully connected lattice with random hopping, subject to a random Heisenberg spin exchange interaction between any pair of sites and a constraint of no double occupancy. A perturbative renormalization group analysis yields a critical point with fractionalized excitations at a nonzero critical value p(c) of the hole doping p away from the half-filled insulator. We compute the renormalization group to two loops, but some exponents are obtained to all loop order. We argue that the critical point p(c) is flanked by confining phases: a disordered Fermi liquid with carrier density 1 + p for p > p(c) and a metallic spin glass with carrier density p for p < p(c). Additional evidence for the critical behavior is obtained from a large-M analysis of a model which extends the SU(2) spin symmetry to SU(M). We discuss the relationship of the vicinity of this deconfined quantum critical point to key aspects of cuprate phenomenology.