# Initialisation of single spin dressed states using shortcuts to adiabaticity

## TL;DR

This paper demonstrates the use of shortcuts to adiabaticity protocols for efficient initialization, control, and readout of coherence-protected dressed states in a single spin, significantly improving transfer speed and fidelity.

## Contribution

It introduces a novel application of shortcuts to adiabaticity for fast, high-fidelity manipulation of dressed states in single spins, enhancing quantum information and sensing capabilities.

## Key findings

- Achieved ~99.4% fidelity in state transfer.
- Accelerated transfer speed by a factor of 2.6.
- Enabled direct readout of dressed state populations.

## Abstract

We demonstrate the use of shortcuts to adiabaticity protocols for initialisation, readout, and coherent control of dressed states generated by closed-contour, coherent driving of a single spin. Such dressed states have recently been shown to exhibit efficient coherence protection, beyond what their two-level counterparts can offer. Our state transfer protocols yield a transfer fidelity of ~ 99.4(2) % while accelerating the transfer speed by a factor of 2.6 compared to the adiabatic approach. We show bi-directionality of the accelerated state transfer, which we employ for direct dressed state population readout after coherent manipulation in the dressed state manifold. Our results enable direct and efficient access to coherence-protected dressed states of individual spins and thereby offer attractive avenues for applications in quantum information processing or quantum sensing.