English

Erratic Liouvillian Skin Localization and Subdiffusive Transport

Quantum Physics 2026-04-08 v2 Disordered Systems and Neural Networks

Abstract

Non-Hermitian systems with globally reciprocal couplings -- such as the Hatano-Nelson model with stochastic imaginary gauge fields -- avoid the conventional non-Hermitian skin effect, displaying erratic bulk localization while retaining ballistic transport. An open question is whether similar behavior arises when non-reciprocity originates at the Liouvillian level rather than from an effective non-Hermitian Hamiltonian obtained via post-selection. Here, a lattice model with globally reciprocal Liouvillian dynamics and locally asymmetric incoherent hopping is investigated, a disordered setting in which Liouvillian-specific effects have remained largely unexplored. While the steady state again shows disorder-dependent, erratic localization without boundary accumulation, {\color{black}excitations in the incoherent-hopping regime spread via {\em Sinai-type subdiffusion}, dramatically slower than ordinary diffusion in symmetric stochastic lattices.} {\color{black}This highlights that the genuinely distinct Liouvillian signature is the coexistence of global reciprocity with ultra-slow, disorder-induced subdiffusive transport, rather than the erratic localization itself.} {\color{black}These results reveal a fundamental distinction between globally reciprocal Hamiltonian and Liouvillian systems: in both cases the skin effect is suppressed, but only in Liouvillian dynamics erratic skin localization can coexist with subdiffusive transport

Keywords

Cite

@article{arxiv.2602.14698,
  title  = {Erratic Liouvillian Skin Localization and Subdiffusive Transport},
  author = {Stefano Longhi},
  journal= {arXiv preprint arXiv:2602.14698},
  year   = {2026}
}

Comments

16 pages, 9 figures, accepted for publication in Quantum Science and Technology (Focus Issue on "Non-Hermitian Quantum Many-Body Physics")

R2 v1 2026-07-01T10:38:25.196Z