Eigenvalue asymptotics for confining magnetic Schr\"odinger operators with complex potentials

TL;DR

This paper analyzes the spectral properties of magnetic Schr"odinger operators with complex potentials in the semiclassical limit, providing a unified framework that extends results from the selfadjoint case to non-selfadjoint operators.

Contribution

It introduces a pseudo-differential effective operator to describe the spectrum of complex-valued electric potentials, extending spectral analysis techniques to non-selfadjoint magnetic Schr"odinger operators.

Findings

Spectral description in various complex plane regions

Extension of selfadjoint spectral results to complex potentials

Accurate characterization of low-lying eigenvalues and spectral gaps

Abstract

This article is devoted to the spectral analysis of the electro-magnetic Schr\"odinger operator on the Euclidean plane. In the semiclassical limit, we derive a pseudo-differential effective operator that allows us to describe the spectrum in various situations and appropriate regions of the complex plane. Not only results of the selfadjoint case are proved (or recovered) in the proposed unifying framework, but new results are established when the electric potential is complex-valued. In such situations, when the non-selfadjointness comes with its specific issues (lack of a "spectral theorem", resolvent estimates), the analogue of the "low-lying eigenvalues" of the selfadjoint case are still accurately described and the spectral gaps estimated.