@article{Chaduteau:2026:10.1103/ljvt-w6hw,
author = {Chaduteau, A and Lee, DKK and Schindler, F},
doi = {10.1103/ljvt-w6hw},
journal = {Physical Review Letters},
title = {Lindbladian versus postselected non-hermitian topology},
url = {http://dx.doi.org/10.1103/ljvt-w6hw},
volume = {136},
year = {2026}
}

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TY  - JOUR
AB  - The recent topological classification of non-Hermitian “Hamiltonians” is usually interpreted in terms of pure quantum states that decay or grow with time. However, many-body systems with loss and gain are typically better described by mixed-state open quantum dynamics, which only correspond to pure-state non-Hermitian dynamics upon a postselection of measurement outcomes. Since postselection becomes exponentially costly with particle number, we here investigate to what extent the most important example of non-Hermitian topology can survive without it: the non-Hermitian skin effect and its relationship to a bulk winding number in one spatial dimension. After defining the winding number of the Lindbladian superoperator for a quadratic fermion system, we systematically relate it to the winding number of the associated postselected non-Hermitian Hamiltonian. We prove that the two winding numbers are equal (opposite) in the absence of gain (loss), and provide a physical explanation for this relationship. When both loss and gain are present, the Lindbladian winding number typically remains quantized and non-zero, though it can change sign at a phase transition separating the loss and gain-dominated regimes. This transition, which leads to a reversal of the Lindbladian skin effect localization, is rendered invisible by postselection. We also identify a case where removing postselection induces a skin effect from otherwise topologically trivial non-Hermitian dynamics.
AU  - Chaduteau,A
AU  - Lee,DKK
AU  - Schindler,F
DO  - 10.1103/ljvt-w6hw
PY  - 2026///
SN  - 0031-9007
TI  - Lindbladian versus postselected non-hermitian topology
T2  - Physical Review Letters
UR  - http://dx.doi.org/10.1103/ljvt-w6hw
UR  - https://doi.org/10.1103/ljvt-w6hw
VL  - 136
ER  - 

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