Heisenberg-limited spin squeezing in a hybrid system with Silicon-Vacancy centers

TL;DR

This paper demonstrates Heisenberg-limited spin squeezing in a hybrid system of Silicon-Vacancy centers and a diamond acoustic waveguide, using modulated microwave fields to realize independent spin interactions, advancing quantum information processing.

Contribution

It introduces a method to generate near-Heisenberg-limited spin squeezing in a SiV center hybrid system via independent control of OAT and TATS interactions.

Findings

Squeezing parameter scales as ~N^{-0.64} close to Heisenberg limit

Squeezing depends on the parity of the total number of spins

Hybrid system enables study of combined spin interactions

Abstract

In this paper, we investigate spin squeezing in a hybrid quantum system consisting of a Silicon-Vacancy (SiV) center ensemble coupled to a diamond acoustic waveguide via the strain interaction. Two sets of non-overlapping driving fields, each contains two time-dependent microwave fields, are applied to this hybrid system. By modulating these fields, the one-axis twist (OAT) interaction and two-axis two-spin (TATS) interaction can be independently realized. In the latter case the squeezing parameter scales to spin number as $\xi_R^2\sim1.61N^{-0.64}$ with the consideration of dissipation, which is very close to the Heisenberg limit. Furthermore, this hybrid system allows for the study of spin squeezing generated by the simultaneous presence of OAT and TATS interactions, which reveals sensitivity to the parity of the number of spins $N_{tot}$, whether it is even or odd. Our scheme enriches the approach for generating Heisenberg-limited spin squeezing in spin-phonon hybrid systems and offers the possibility for future applications in quantum information processing.