A squeezed nonlinear mechanical oscillator (Part I)

Circuit quantum acoustodynamics (cQAD) integrates mechanical resonators with superconducting circuits. It combines high-quality factor, small footprint mechanical modes with the large nonlinearity of Josephson junctions. Recent advances in this field have enabled preparation and characterization of mechanical quantum states as well as parametric operations between phonon modes [1].



One particularly useful single-mode operation is squeezing, which can be used to generate mechanical states for quantum sensing, simulations, and information processing [2]. In a two-part presentation, we demonstrate the engineered squeezing of a bulk acoustic wave mechanical mode. This first talk focuses on how we implement an effective two-phonon drive in our device, resulting in a squeezing interaction. We then study the dependence of the interaction strength on different system parameters and use our insights to create a squeezed state of mechanical motion.



[1] von Lüpke, U. et al. (2023) arXiv preprint arXiv:2303.00730

[2] Wang, C. S. et al. (2020) Physical Review X, 10(2), 021060