Variational principle for time-periodic quantum systems

TL;DR

This paper introduces a variational principle for calculating Floquet states in time-periodic quantum systems, enabling efficient analysis of high-dimensional systems and providing a new computational approach.

Contribution

It formulates a novel variational principle for Floquet states and demonstrates its effectiveness on a solvable harmonic oscillator model.

Findings

Successfully tested against an analytically solvable model

Enables tracing Floquet states through parameter space

Potential for application to high-dimensional systems

Abstract

A variational principle enabling one to compute individual Floquet states of a periodically time-dependent quantum system is formulated, and successfully tested against the benchmark system provided by the analytically solvable model of a linearly driven harmonic oscillator. The principle is particularly well suited for tracing individual Floquet states through parameter space, and may allow one to obtain Floquet states even for very high-dimensional systems which cannot be treated by the known standard numerical methods.