Holographic Non-Hermitian Lattices and Junctions with PT-Restoring RG Flows

Résumé : We construct and study inhomogenoeus non-Hermitian strongly coupled holographic field theories. We consider two models: a lattice where in each site there is some inflow/outflow of matter and a Hermitian/non-Hermitian/Hermitian junction. Depending on whether we turn on a complex external gauge field, we find solutions that spontaneously break PT (thus hinting at a lack of unitary evolution) and solutions that do not. The former present an imaginary current responsible for the spontaneous breaking of PT. We also study the IR geometry of these solutions finding that they flow to a PT-unbroken fixed point. This leads us to claim that there is a PT-symmetry restoration in the IR, similar to the one observed in the perturbative setup of arXiv:2110.05289.