Experimentally mimicking squeezed vacuum using parametric drives

Squeezed light is a useful resource in quantum technologies due to its inherent correlations. A particularly compelling and useful application is to use squeezed light to generate entanglement as well as extend the transverse coherence time (T₂) beyond the ordinary vacuum decay limit (2T₁) [1]. However, using squeezed light in the microwave domain presents challenges, due to difficulties in both generating significant squeezing and transmitting with minimal loss. Here we implement an alternative approach, based on a recent theory proposal [2], with the aim of mimicking squeezed vacuum by parametrically driving a tunable coupler placed between a Josephson junction-based superconducting qubit and a microwave resonator. We report on recent experimental results in this effort.

[1] Murch, K., Weber, S., Beck, K. et al. Reduction of the radiative decay of atomic coherence in squeezed vacuum. Nature 499, 62–65 (2013). https://doi.org/10.1038/nature12264

[2] Stabilizing two-qubit entanglement by mimicking a squeezed environment, L. C. G. Govia, A. Lingenfelter, and A. A. Clerk, Phys. Rev. Research 4, 023010 (2022)

https://doi.org/10.1103/PhysRevResearch.4.023010