A hybrid-systems approach to spin squeezing using a highly dissipative ancillary system

TL;DR

This paper introduces a hybrid-systems method for generating spin squeezed states using a highly dissipative ancillary system, leveraging dissipation as a resource for quantum metrology.

Contribution

It demonstrates that spin squeezing can be achieved via two mechanisms in a dissipative hybrid system, with tunable interpolation between them, and explores practical implementations with superconducting circuits.

Findings

Spin squeezing can be generated through one-axis twisting and driven collective relaxation.

Ancillary system dissipation can positively contribute to spin squeezing.

Feasible experimental setups with superconducting circuits for hundreds of spins.

Abstract

Squeezed states of spin systems are an important entangled resource for quantum technologies, particularly quantum metrology and sensing. Here we consider the generation of spin squeezed states by interacting the spins with a dissipative ancillary system. We show that spin squeezing can be generated in this model by two different mechanisms: one-axis twisting and driven collective relaxation. We can interpolate between the two mechanisms by simply adjusting the detuning between the dissipative ancillary system and the spin system. Interestingly, we find that for both mechanisms, ancillary system dissipation need not be considered an imperfection in our model, but plays a positive role in spin squeezing. To assess the feasibility of spin squeezing we consider two different implementations with superconducting circuits. We conclude that it is experimentally feasible to generate a squeezed state of hundreds of spins either by one-axis twisting or by driven collective relaxation.