Z2 non-Hermitian skin effect in equilibrium heavy-fermion systems

Abstract

We demonstrate that a correlated equilibrium $f$-electron system with time-reversal symmetry can exhibit a ${\mathbb{Z}}_{2}$ non-Hermitian skin effect of quasiparticles. In particular, we analyze a two-dimensional periodic Anderson model with spin-orbit coupling by combining the dynamical mean-field theory (DMFT) and the numerical renormalization group. We prove the existence of the ${\mathbb{Z}}_{2}$ skin effect by explicitly calculating the topological invariant and show that spin-orbit interaction is essential to this effect. Our DMFT analysis demonstrates that the ${\mathbb{Z}}_{2}$ skin effect of quasiparticles is reflected on the pseudospectrum. Furthermore, we analyze temperature effects on this skin effect using the generalized Brillouin zone technique, which clarifies that the skin modes are strongly localized above the Kondo temperature.