2 papers
cond-mat.str-el2026
On the Symmetries of Anisotropic Spin Interaction Models
Arist Zhenyuan Yang
We show that anisotropic spin interactions do not merely break spin-space group (SSG) symmetries, but instead twist them through cohomology invariants, yielding symmetry classes be…
cond-mat.str-el2026
Spin-Charge Groups for Fermions in Fluids and Crystals: General Structures and Physical Consequences
Arist Zhenyuan Yang, Zheng-Xin Liu
Known symmetry groups are insufficient to describe the various couplings among spin, charge, and spatial degrees of freedom in fermionic systems. To address this problem, we introd…