2020/03/06 by Linhu Li, Ching Hua Lee, Sen Mu +1 · 5 citations
Physics and Astronomy · #cond-mat.mes-hall #quant-ph
paper · pdf · doi:10.1038/s41467-020-18917-4
published as NATURE COMMUNICATIONS 11, Article number 5491 (2020) · 4+ pages of main text (including 4 figures), plus 6 pages of Supplementary Material (including 7 figures)
arxiv created 2020/03/06 · arxiv updated 2020/11/03
This work uncovers a new class of criticality where eigenenergies and eigenstates of non-Hermitian lattice systems jump discontinuously across a critical point in the thermodynamic limit, unlike established Hermitian and non-Hermitian critical scenarios where spectrum remains continuous across a transition. Such critical behavior, dubbed the "critical skin effect", is rather generic, occuring whenever subsystems with dissimilar non-Hermitian skin localization lengths are coupled, however weakly. Due to the existence of this criticality, the thermodynamic limit and the zero-coupling limit cannot be exchanged, thus challenging the celebrated generalized Brillouin zone (GBZ) approach when applied to finite-size systems. As manifestations of the critical skin effect in finite-size systems, we present stimulating examples with anomalous scaling behavior regarding spectrum, correlation functions, entanglement entropy, and scale-free wavefunctions that decay exponentially rather than power-law. More spectacularly, topological in-gap modes can even be induced by changing the system size.