Speaker
Description
Abstract
Weyl semimetals require the breaking of either time-reversal symmetry or inversion symmetry (or both). PrAlGe is a noncentrosymmetric material whose crystal structure lacks inversion symmetry and is widely considered to exhibit a ferromagnetic ground state that additionally breaks time-reversal symmetry. This additional breaking of time-reversal symmetry is expected to modify the Weyl band structure. Although the ground state is believed to be ferromagnetic, magnetic susceptibility measurements performed under a very small external magnetic field reveal a bifurcation starting at 15 K. In addition, time-dependent magnetic moment measurements exhibit extremely slow magnetic relaxation following the application of a magnetic field, with glassy behavior observed down to 1.6 K. These two observations suggest a glassy magnetic state rather than a ferromagnetic state. Anomalous Hall effect measurements, which probe the Berry curvature associated with the Weyl points, also reveal hysteresis that depends on the magnetic-field sweep rate, suggesting a possible connection between slow magnetic dynamics and the Berry phase. Our findings raise important questions about how glassy magnetism may coexist with or modify Berry-curvature-induced anomalous Hall transport in magnetic Weyl semimetals.
Keywords: PrAlGe; Weyl semimetals; spin-glass-like magnetism;
Hall transport; magnetic relaxation; Hall hysteresis.
