Magnetic field and temperature dependence of anomalous transport properties in YbCuAS₂ Kondo lattice compound

YbCuAs₂ has been characterized as an antiferromagnetic Kondo Lattice system with T_N ~ 3.7 K. Previously, the magnetic field dependences of the electrical resistivity, specific heat, and magnetization show the unusual hysteresis loop, persisting even above the magnetic ordering temperature [1]. Motivated by the magnetic field dependent hysteresis, Hall resistivity and thermoelectric power measurements are performed to understand the origin of the hysteresis. Interestingly, both Hall and thermoelectric power indicate a large hysteresis loop over the wide range of temperature, which was not observed in earlier thermodynamic and transport measurements. In this talk, we will discuss the anomalous hysteresis loop in regarding a valence instability of Yb-ions in YbCuAs₂.

[1] David Evans, et al., PHYSICAL REVIEW B 105, 085105 (2022)