Strong instability of standing waves for $L^2$-supercritical Schrödinger-Poisson system with a doping profile
Mathieu Colin, Tatsuya Watanabe
TL;DR
The paper analyzes strong instability of standing waves for the $L^2$-supercritical Schrödinger-Poisson system with a doping profile, establishing instability of ground states under small coupling and doping effects. It develops a new energy inequality along the $L^2$-invariant scaling and adopts the Fukaya-Ohta framework to trigger finite-time blow-up via a virial identity, without requiring a fixed frequency. When the doping is a characteristic function on a bounded domain, instability is linked to geometric quantities such as mean curvature, with a sharp boundary-trace argument and moving-surface calculus enabling a smallness condition on domain geometry to guarantee instability. The results extend the instability theory for nonlocal, inhomogeneous media and demonstrate how inhomogeneities and geometry influence the dynamics of standing waves in Schrödinger-Poisson systems.
Abstract
This paper is devoted to the study of the nonlinear Schrödinger-Poisson system with a doping profile. We are interested in the strong instability of standing waves associated with ground state solutions in the $L^2$-supercritical case. The presence of a doping profile causes several difficulties, especially in examining geometric shapes of fibering maps along an $L^2$-invariant scaling curve. Furthermore, the classical approach by Berestycki-Cazenave for the strong instability cannot be applied to our problem due to a remainder term caused by the doping profile. To overcome these difficulties, we establish a new energy inequality associated with the $L^2$-invariant scaling and adopt the strong instability result developed by Fukaya-Ohta(2018). When the doping profile is a characteristic function supported on a bounded smooth domain, some geometric quantities related to the domain, such as the mean curvature, are responsible for the strong instability of standing waves.
