2020/09/30 by Cong Xiao, Qian Niu · 1 citation
Materials Science · Physics and Astronomy · #Angular momentum #Berry connection and curvature #Condensed matter physics #Cooper pair #Current (fluid) #Dipole #Electron #Geometric phase #Iron-based superconductors research #Magnetic anisotropy #Magnetic field #Magnetization #Orbital magnetization #Pairing #Physics #Physics of Superconductivity and Magnetism #Quantum #Quantum electrodynamics #Quantum mechanics #Quasiparticle #Semiclassical physics #Spin (aerodynamics) #Superconductivity #Topological Materials and Phenomena #cond-mat.mes-hall #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.104.l241411
published in Physical review. B./Physical review. B 104(24) (American Physical Society) · 4 pages
arxiv created 2021/09/06 · openalex publication_date 2021/12/27 · arxiv updated 2022/01/05 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
We provide a unified semiclassical theory for the conserved current of nonconserved quantities, and manifest it in two physical contexts: the spin current of Bloch electrons and the charge current of mean-field Bogoliubov quasiparticles. We reveal that the previously overlooked torque quadrupole density and Berry phase correction to the torque dipole density are essential to assure a circulating spin current with null net flow at equilibrium. The band geometric origin of spin transport is ascertained to be the momentum space Berry curvature instead of the spin Berry curvature, paving the way for material related studies. In superconductors the attained conserved charge current corresponds to the quasiparticle charge current renormalized by the condensate backflow. Its circulation at equilibrium gives an orbital magnetization, which involves the characteristics of superconductivity, such as the Berry curvature arising from unconventional pairing and an orbital magnetic moment induced by the charge dipole of moving quasiparticles.