Harmonic dual dressing of spin-1/2 systems

Year: 2022

Authors: Bevilacqua G.,Biancalana V., Zanon-Willette T., Arimondo E.

Autors Affiliation: Department of Physical Sciences, Earth and Environment ? DSFTA, University of Siena, Italy; Sorbonne University, Observatoire de Paris, University PSL, CNRS, LERMA, Paris, F-75005, France; MajuLab, CNRS-UCA-SU-NUS-NTU International Joint Research Unit, Singapore, Singapore; Centre for Quantum Technologies, National University of Singapore, Singapore, 117543, Singapore; Dipartimento di Fisica E. Fermi, Universita di Pisa – Largo B., Pontecorvo 3, Pisa, 56127, Italy; INO-CNR, Via G. Moruzzi 1, Pisa, 56124, Italy

Abstract: Controlled modifications of the magnetic response of a two-level system are produced in dressed systems by one high-frequency, strong, and nonresonant electromagnetic field. This quantum control is greatly enhanced and enriched by a harmonic, commensurable, and orthogonally oriented dual dressing, as discussed here. The secondary field enables a fine tuning of the qubit response, with control parameter amplitude, harmonic content, spatial orientation, and phase relation. Our analysis, mainly based on a perturbative approach with respect to the driving strength, includes also nonperturbative numerical solutions. The Zeeman response becomes anisotropic in a triaxial geometry and includes a nonlinear quadratic contribution. The long-time dynamics is described by an anisotropic effective magnetic field representing the handle for the system full engineering. Through the low-order harmonic mixing, the bichromatic driving generates a synthetic static field modifying the system dynamics. The spin temporal evolution includes a micromotion at harmonics of the driving frequency whose role in the spin detection is examined. Our dressing increases the two-level energy splitting, improving the spin detection sensitivity. In the weak-field direction it compensates the static fields applied in different geometries. The results presented here lay a foundation for additional applications to be harnessed in quantum simulations.


Volume: 105 (2)      Pages from: 022619-1  to: 022619-15

More Information: The authors thank Helene Perrin, Andrea Tomadin, and Sandro Wimberger for a careful reading and constructive comments regarding the manuscript. G.B. is partially supported by GNFM of Indam.
DOI: 10.1103/PhysRevA.105.022619