论文标题
旋转浆果曲率和旋转Chern标记的光学吸收测量
Optical absorption measurement of spin Berry curvature and spin Chern marker
论文作者
论文摘要
在Dirac模型描述的二维时间反转对称性拓扑绝缘子中，可以用Spin Chern编号来描述$ {\ Mathbb Z} _ {2} $拓扑不变。我们为自旋浆果曲率提出了线性响应理论，该理论将其整合到旋转的Chern数字中，并引入其光谱函数，可以通过动量和自旋分辨的圆形二分色症在有限温度下测量，这可以通过使用旋转和时间分辨的Arpes来实现泵的实验类型。结果，可以直接测量$ {\ mathbb z} _ {2} $不变的pfaffian的符号。在真实空间中表达的旋转Chern数产生了一个自旋切尔标记，其空间变化可以通过圆形二色性和旋转分辨的光发射以空间分辨率进行测量。旋转的Chern相关器和非局部自旋切尔标记进一步提出了拓扑相变附近的量子临界点，这些量子相变附近，这些量子临界值显示出在自旋选择的Wannier状态之间的重叠形式。
In two-dimensional time-reversal symmetric topological insulators described by Dirac models, the ${\mathbb Z}_{2}$ topological invariant can be described by the spin Chern number. We present a linear response theory for the spin Berry curvature that integrates to the spin Chern number, and introduce its spectral function that can be measured at finite temperature by momentum- and spin-resolved circular dichroism, which may be achieved by pump-probe type of experiments using spin- and time-resolved ARPES. As a result, the sign of the Pfaffian of the ${\mathbb Z}_{2}$ invariant can be directly measured. The spin Chern number expressed in real space yields a spin Chern marker, whose spatial variation may be measured by circular dichroism and spin-resolved photoemission with a spatial resolution. A spin Chern correlator and a nonlocal spin Chern marker are further proposed to characterize the quantum criticality near topological phase transitions, which are shown to take the form of overlaps between spin-selected Wannier states.
