TY  - JOUR
PB  - SciPost Foundation
DO  - 10.21468/SciPostPhys.19.2.036
TI  - Anderson impurities in edge states with nonlinear and dissipative perturbations
PY  - 2025/08/13
UR  - https://www.scipost.org/SciPostPhys.19.2.036
JF  - SciPost Physics
JA  - SciPost Phys.
VL  - 19
IS  - 2
SP  - 036
A1  - Kulkarni, Vinayak M.
AU  - Vidhyadhiraja, N. S.
AB  - We show that exceptional points (EPs) and non-Hermitian behavior can emerge dynamically in impurity models with Hermitian microscopic origins. Using perturbative renormalization group (RG) analysis, Fock-space diagonalization, and spin-spin relaxation time calculations, we demonstrate that nonlinear (NL) dispersion and anisotropic pseudochiral ($\mathcal{PC}$) interactions generate complex fixed points and spectral defectiveness. The effective Kondo model features a square-root RG invariant linking planar and longitudinal Dzyaloshinskii-Moriya (DM) couplings, driving the onset of EPs. Our analysis reveals dissipative fixed points stabilized by an emergent Lie algebra structure and a scaling collapse in relaxation dynamics. Across both single- and two-impurity extensions, we identify a universal "sign-reversion" (SR) regime near critical NL coupling, where anisotropy preserves $\mathcal{PC}$ symmetry and SR serves as a signature of non-Hermitian flow. These results establish a new class of non-Hermitian criticality generated through RG evolution in otherwise Hermitian systems.
ER  -

@Article{10.21468/SciPostPhys.19.2.036,
	title={{Anderson impurities in edge states with nonlinear and dissipative perturbations}},
	author={Vinayak M. Kulkarni and N. S. Vidhyadhiraja},
	journal={SciPost Phys.},
	volume={19},
	pages={036},
	year={2025},
	publisher={SciPost},
	doi={10.21468/SciPostPhys.19.2.036},
	url={https://scipost.org/10.21468/SciPostPhys.19.2.036},
}