Edge states of periodically kicked quantum rotors

TL;DR

This paper discovers a unique edge localization phenomenon in periodically kicked 3D quantum rotors, which impacts molecular rotation excitation and differs from 2D rotor behavior.

Contribution

It introduces the concept of edge localization in 3D quantum rotors and demonstrates its significance under fractional quantum resonance conditions.

Findings

Edge states are localized near J=0 in 3D rotors.

Edge localization influences resonant molecular rotation excitation.

The phenomenon is absent in 2D rotors.

Abstract

We present a quantum localization phenomenon that exists in periodically kicked 3D rotors, but is absent in the commonly studied 2D ones: edge localization. We show that under the condition of a fractional quantum resonance there are states of the kicked rotor that are strongly localized near the edge of the angular momentum space at $J=0$. These states are analogs of surface states in crystalline solids, and they significantly affect resonant excitation of molecular rotation by laser pulse trains.