Non-Hermitian skin effect in a semi-infinite Fock-state lattice
Phys. Rev. A 114, 022403 – Published 4 August, 2026
DOI: https://doi.org/10.1103/y7bs-4pkl
Abstract
In this paper, we investigate the non-Hermitian skin effect in a semi-infinite Fock-state lattice, where the inherent coupling between neighboring Fock states scales as with denoting the phonon number or lattice site index. By analytically solving a nonuniform, nonreciprocal Su-Schrieffer-Heeger model, we demonstrate that the intrinsic inhomogeneous coupling, in combination with nonreciprocity, fundamentally modifies the conventional skin effect. Instead of accumulating at the physical boundary, all eigenmodes become compressed and skewed within a finite spatial range determined by the inhomogeneous profile. Consequently, the evolution of the probability distribution on the lattice starting from a single site is doubly confined: it is spatially bounded to a finite range by the inhomogeneous coupling, and further restricted to a one-sided trajectory at the edge of this range by the nonreciprocity. Moreover, a feasible experimental scheme based on a single trapped ion is also proposed. This work reveals how engineered coupling profiles in synthetic dimensions can reshape non-Hermitian properties and enable protocols for quantum state manipulation.