Harmonic dual dressing of spin one-half systems

TL;DR

This paper introduces a dual harmonic dressing technique for spin-1/2 systems, enabling precise control of magnetic responses, enhanced sensitivity, and potential applications in quantum information and simulations.

Contribution

It presents a novel dual harmonic dressing method that allows fine-tuning of spin responses and facilitates resonant spin exchange in quantum systems.

Findings

Enhanced spin detection sensitivity due to increased energy splitting.

Compensation of static fields through bichromatic driving.

Enabling resonant spin exchange between different magnetic species.

Abstract

Controlled modifications of the quantum magnetic response are produced in dressed systems by a high frequency, strong and not-resonant electromagnetic field. This quantum control is greatly enhanced and enriched by the harmonic, commensurable and orthogonally oriented dual dressing theoretically discussed here. The secondary field enables a fine tuning of the qubit response, with control parameters amplitude, harmonic content, spatial orientation and phase relation. Our analysis is based on a perturbative approach and includes few numerical solutions. The long-time dynamics is described in terms of an anisotropic effective static magnetic field representing the handle for the system full engineering. Through a low-order harmonic mixing the bichromatic driving generates a rectified static field acting on the spin. The Zeeman response becomes anisotropic in a triaxial geometry and includes a quadratic contribution. Our dressing increases the two-level energy splitting, improving the spin detection sensitivity. On the low field direction it compensates the static fields applied in different geometries. A resonant spin exchange between two species having very different magnetic response as electron and nucleus is allowed by the dressing. The spin temporal evolution includes a micromotion at harmonics of the driving frequency whose role in the spin detection is examined and can be exploited in quantum information. The results presented here lay a foundation for additional applications to be harnessed in quantum simulations.