Wang Zhi, Dong Liang, Xiao Cong, Niu Qian
School of Physics, Sun Yat-sen University, Guangzhou 510275, China.
Department of Physics, The University of Texas at Austin, Austin, Texas 78712, USA.
Phys Rev Lett. 2021 May 7;126(18):187001. doi: 10.1103/PhysRevLett.126.187001.
We construct a theory for the semiclassical dynamics of superconducting quasiparticles by following their wave packet motion and reveal rich contents of Berry curvature effects in the phase space spanned by position and momentum. These Berry curvatures are traced back to the characteristics of superconductivity, including the nontrivial momentum-space geometry of superconducting pairing, the real-space supercurrent, and the charge dipole of quasiparticles. The Berry-curvature effects strongly influence the spectroscopic and transport properties of superconductors, such as the local density of states and the thermal Hall conductivity. As a model illustration, we apply the theory to study the twisted bilayer graphene with a d_{x^{2}+y^{2}}+id_{xy} superconducting gap function and demonstrate Berry-curvature induced effects.
我们通过追踪超导准粒子的波包运动，构建了一个关于其半经典动力学的理论，并揭示了在由位置和动量所跨越的相空间中贝里曲率效应的丰富内容。这些贝里曲率可追溯到超导的特性，包括超导配对的非平凡动量空间几何结构、实空间超电流以及准粒子的电荷偶极子。贝里曲率效应强烈影响超导体的光谱和输运性质，如态密度和热霍尔电导率。作为一个模型示例，我们应用该理论研究具有(d_{x^{2}+y^{2}}+id_{xy})超导能隙函数的扭曲双层石墨烯，并展示贝里曲率诱导效应。
