Symmetry-Fractionalized Skin Effects in Non-Hermitian Luttinger Liquids

TL;DR

This paper explores how symmetry sector decoupling in non-Hermitian Luttinger liquids leads to skin effects, demonstrated through models like the Hubbard model and an interaction-enabled E8 skin effect.

Contribution

It extends the concept of symmetry sector decoupling to non-Hermitian systems, revealing novel skin effects and constructing an interaction-enabled E8 skin effect.

Findings

Spin and charge skin effects separate at low energies in the Hubbard model.

Demonstrated emergent decoupling of symmetry sectors in non-Hermitian systems.

Constructed an interaction-enabled E8 skin effect with no free fermion counterpart.

Abstract

In one dimension, strongly correlated gapless systems are highly constrained due to conformal invariance, leading to the decoupling of low energy degrees of freedom corresponding to different symmetry sectors. The most familiar example of this is spin-charge separation. Here, we extend this mechanism to the non-Hermitian realm by demonstrating that skin effects corresponding to different symmetry sectors exhibit an emergent decoupling. We establish this for $N$ flavor fermions and demonstrate it numerically for the special case of the Hubbard model, in which spin and charge skin effects separate at low energies. Finally, we construct an interaction-enabled $E_8$ skin effect with no free fermion counterpart.