Calculation for polar Kerr effect in high-temperature cuprate superconductors

Abstract

A mechanism is proposed for the tantalizing evidence of polar Kerr effect in a class of high temperature superconductors-the signs of the Kerr angle from two opposite faces of the same sample are identical and magnetic field training is non-existent. The mechanism does not break global time reversal symmetry, as in an antiferromagnet, and results in zero Faraday effect. It is best understood in a phenomenological model of bilayer cuprates, such as YBa2Cu3O 6+δ , in which intra-bilayer tunneling nucleates a chiral d-density wave such that the individual layers have opposite chirality. Although specific to the chiral d-density wave, the mechanism may be more general to any quasi-two-dimensional orbital antiferromagnet in which time reversal symmetry is broken in each plane, but not when averaged macroscopically.

Anomalous Hall transport in tilted multi-Weyl semimetals

“…In the type-II phase it has been shown to be non-universal in the minimal model [64]. AHE and the thermal Hall and Nernst coefficients have been calculated in the minimal model of type-I and type-II WSMs [64,[66][67][68], in a perpendicular magnetic field [65,69] (no tilt), and in lattice models [70,71], with subsequent experimental validation [72][73][74]. The thermo-electric effect has been studied semi-classically in WSMs [75][76][77] with Berry curvature effects [78] using the Boltzmann formalism.…”