# Spin resonance under topological driving fields

## TL;DR

This paper investigates how topological properties of a periodically driven magnetic field influence the dynamics of a spin-1/2 system, revealing topological signatures in Floquet states despite non-adiabatic effects.

## Contribution

It demonstrates that the topology of the driving field leaves a clear imprint on Floquet spin states via an effective Berry phase, suggesting new experimental ways to detect topological transitions.

## Key findings

- Topological transition affects Floquet spin states.
- Effective Berry phase emerges in quasienergy.
- Spin resonance conditions are altered by topology.

## Abstract

We study the dynamics of a localized spin-1/2 driven by a time-periodic magnetic field that undergoes a topological transition. Despite the strongly non-adiabatic effects dominating the spin dynamics, we find that the field's topology appears clearly imprinted in the Floquet spin states through an effective Berry phase emerging in the quasienergy. This has remarkable consequences on the spin resonance condition suggesting a whole new class of experiments to spot topological transitions in the dynamics of spins and other two-level systems, from nuclear magnetic resonance to strongly-driven superconducting qubits.