A squeezed nonlinear mechanical oscillator (Part II)

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. In this second talk, we investigate the interplay of the strength and detuning of the squeezing operation, together with the mode nonlinearity. By performing Wigner tomography, we show the time dynamics of the squeezed state and its evolution into a non-Gaussian quantum state in certain parameter regimes.



[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