2025/04/17 by Matthaiakakis, Ioannis, Jia, Weizhen, Klees, Raffael L. +5 · 1 citation
#FOS: Physical sciences #High Energy Physics - Theory (hep-th) #Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
paper · doi:10.48550/arxiv.2504.13250
This work focuses on the non-dissipative, parity-odd spin transport of (2 + 1)-dimensional relativistic electrons, generated by torsion, and the torsional Hall viscosity ζH. We first determine ζH for massive Dirac fermions in the presence of a constant electromagnetic field. We predict that the magnetic field induces a contribution to ζH competing with the one originating from the Dirac mass. Moreover, we quantify the impact on ζH originating from the band structure deformation quadratic in momentum terms that was proposed by Bernevig-Hughes-Zhang (BHZ). We find that the BHZ deformation enhances ζH in magnitude, but reverses its sign as compared to the standard massive Dirac fermion, indicating a Hall response in opposite direction to the typical Hall viscous force. Nevertheless, the torsional Hall viscosity still discriminates between topologically trivial and non-trivial regimes. Our results, hence, pave the way for a deeper understanding of hydrodynamic spin transport and its possible verification in experiments.