Non-Hermitian skin effect and self-acceleration

Non-Hermitian systems exhibit nontrivial band topology and a strong sensitivity of the energy spectrum on boundary conditions. Remarkably, macroscopic number bulk states get squeezed toward lattice edges under open conditions, an effect dubbed non-Hermitian skin (NHSE). A well-established dynamical signature NHSE in real space is directional flow (or persistent current) for arbitrary initial excitation system, which observed at long times. Here we unravel different that manifests itself early-time dynamics namely, self-acceleration wave function. Self-acceleration demonstrated to occur rather generally single--band models probed by single-site excitation, where acceleration turns out be proportional area enclosed Bloch Hamiltonian periodic The observation packet early times clear should experimentally accessible using synthetic matter, example, discrete-time photonic quantum walks.