Minimum requirements for laser-induced symmetry breaking in quantum and classical mechanics

TL;DR

This paper establishes the necessary conditions for laser-induced symmetry breaking in symmetric systems, showing these conditions are identical in quantum and classical mechanics and depend on anharmonicity and symmetry violations.

Contribution

It identifies the fundamental symmetry and anharmonicity requirements for phase controllability in laser-driven systems, unifying quantum and classical perspectives.

Findings

Anharmonicities are necessary for phase controllability.

Identifies common temporal symmetry conditions for classical and quantum systems.

Provides a unified framework for understanding laser-induced transport in symmetric systems.

Abstract

Necessary conditions for generating phase controllable asymmetry in spatially symmetric systems using lasers are identified and are shown to be identical in quantum and classical mechanics. First, by studying the exact dynamics of harmonic systems in the presence of an arbitrary radiation field, it is demonstrated that anharmonicities in the system's potential are a necessary requirement for phase controllability. Then, by analyzing the space-time symmetries of the laser-driven Liouville dynamics for classical and quantum systems, a common set of temporal symmetries for the driving field that need to be violated to induce transport are identified. The conditions apply to continuous wave lasers and to symmetry breaking effects that do not rely on the control of the absolute phase of the field. Known examples of laser fields that can induce transport in symmetric systems are seen to be particular cases of these symmetry constraints.