论文标题
掺杂引起的量子自旋霍尔绝缘子到超导体过渡
Doping-induced quantum spin Hall insulator to superconductor transition
论文作者
论文摘要
动态生成的量子自旋霍尔状态的独特属性是戈德石模式，与自旋轨道耦合顺序参数的长波长波动相对应，其拓扑天空激发带有电荷2 $ e $。在此处考虑的模型中，在改变化学电位后，我们观察到了两个过渡：S波超导顺序参数以关键的化学势$μ__{C1} $开发，对应于一对效率的激发差距，以及$μ__{C2} $ so（3）so（3）量子的量子参数的量子级别量式量霍尔厅的量子。使用无负符号的大规模量子蒙特卡洛模拟，我们表明$μ_{c1} =μ_{c2} $在我们的准确性内 - 我们可以将兴奋剂从一半填充到$δ= 0.0017 $中。与量子旋转大厅顺序参数波动相关的长度比例生长到我们最低的掺杂，表明连续或弱的一阶转变。与平均场期望相反，掺杂与化学势曲线不是线性的，如果过渡是连续的，则表明动态关键指数$ z> 2 $。
A unique property of a dynamically generated quantum spin Hall state are Goldstone modes that correspond to the long-wavelength fluctuations of the spin-orbit coupling order parameter whose topological Skyrmion excitations carry charge 2$e$. Within the model considered here, upon varying the chemical potential, we observe two transitions: An s-wave superconducting order parameter develops at a critical chemical potential $μ_{c1}$, corresponding to the excitation gap of pairs of fermions, and at $μ_{c2}$ the SO(3) order parameter of the quantum spin Hall state vanishes. Using negative-sign-free, large-scale quantum Monte Carlo simulations, we show that $μ_{c1}=μ_{c2}$ within our accuracy -- we can resolve dopings away from half filling down to $δ= 0.0017$. The length scale associated with the fluctuations of the quantum spin Hall order parameter grows down to our lowest doping, suggesting either a continuous or a weakly first-order transition. Contrary to mean-field expectations, the doping versus chemical potential curve is not linear, indicating a dynamical critical exponent $z > 2$ if the transition is continuous.
