$H^1$ local exact controllability of some one-dimensional bilinear Schr{ö}dinger equations
Nabile Boussaïd, Alessandro Duca
TL;DR
This work investigates local exact controllability of a one-dimensional bilinear Schrödinger equation under Dirichlet and periodic boundary conditions, incorporating discontinuous control potentials and a constant magnetic field. It demonstrates local exact controllability in $H^1_0$ for Dirichlet via a diffusion of spectral couplings and a moment-problem—solvable through an inverse mapping theorem—alongside local controllability in $H^1_p$ under Zeeman-type spectral decoupling in the periodic setting. The results rely on careful well-posedness in low-regularity spaces, endpoint-map $C^1$ regularity, and spectral/gauge-based arguments, with explicit coupling conditions $|ig<\mu\phi_l,\phi_k\big>|\ge C/(|k|+1)$ and non-resonant spectra. In the harmonic oscillator, the authors obtain global exact controllability for the linearized system within a weighted Hermite-space framework, clarifying the reachable subspaces and outlining open problems for Neumann boundaries and full nonlinear controllability.
Abstract
The local exact controllability of the one-dimensional bilinear Schr{ö}dinger equation with Dirichlet boundary conditions has been extensively studied in subspaces of H 3 since the seminal work of K. Beauchard. Our first objective is to revisit this result and establish the controllability in H 1 0 for suitable discontinuous control potentials. In the second part, we consider the equation in the presence of periodic boundary conditions and a constant magnetic field. We prove the local exact controllability of periodic H 1 -states, thanks to a Zeeman-type effect induced by the magnetic field which decouples the resonant spectrum. Finally, we discuss open problems and partial results for the Neumann case and the harmonic oscillator.
