论文标题
在随机$ t $ -j $型号中以非零掺杂的量子相变
Quantum phase transition at non-zero doping in a random $t$-$J$ model
论文作者
论文摘要
我们在$ t $ -j $ j $ spin-1/2电子的有限簇上提供了确切的对角线化结果，并随机全能跳转和交换互动。我们认为，这种随机模型在定性上捕获了描述丘比特和相关化合物所需的强局部相关性，同时避免了晶格空间组对称性破坏顺序。在掺杂$ p = 0 $的绝缘体中，先前已知的自旋玻璃有序相位延伸到金属自旋玻璃相，直至过渡$ p = p_c \ of 1/3 $。动态自旋敏感性显示了$ p_c $附近的sachdev-ye-kitaev型号频谱的签名。我们还发现了熵，纠缠熵和可压缩性中相变的迹象，所有这些均显示了最大$ P_C $。金属相中的电子能量分布函数与$ p> p_c $的Luttinger-volume-Fermi表面的无序扩展一致，而对于$ p <p_c $，这会分解。
We present exact diagonalization results on finite clusters of a $t$-$J$ model of spin-1/2 electrons with random all-to-all hopping and exchange interactions. We argue that such random models capture qualitatively the strong local correlations needed to describe the cuprates and related compounds, while avoiding lattice space group symmetry breaking orders. The previously known spin glass ordered phase in the insulator at doping $p=0$ extends to a metallic spin glass phase up to a transition $p=p_c \approx 1/3$. The dynamic spin susceptibility shows signatures of the spectrum of the Sachdev-Ye-Kitaev models near $p_c$. We also find signs of the phase transition in the entropy, entanglement entropy and compressibility, all of which exhibit a maximum near $p_c$. The electron energy distribution function in the metallic phase is consistent with a disordered extension of the Luttinger-volume Fermi surface for $p>p_c$, while this breaks down for $p<p_c$.
