Optically probing Schwinger angular momenta in a micromechanical resonator

作者：Motoki Asano, Ryuichi Ohta, Takuma Aihara, Tai Tsuchizawa, Hajime Okamoto, Hiroshi Yamguchi · 发表于：Physical Review A · 年份：2019 · DOI：10.1103/physreva.100.053801 · 被引用次数：8 · 研究领域：Mechanical and Optical Resonators、Force Microscopy Techniques and Applications、Advanced MEMS and NEMS Technologies

We report an observation of phononic Schwinger angular momenta, which fully represent two-mode states in a micromechanical resonator. This observation is based on simultaneous optical detection of the mechanical response at the sum and difference frequency of the two mechanical modes. A postselection process for the measured signals allows us to extract a component of phononic Schwinger angular momenta. This postselection scheme with the nonlinear measurement enables us to conditionally prepare two-mode states, which shows a noise reduction along a cross-phase quadrature and a finite correlation, from a randomly excited (uncorrelated) state. The phononic Schwinger angular momenta could be extended to high-dimensional symmetry [e.g., SU($N$) group] for studying multipartite correlations in nonequilibrium dynamics with macroscopic objects.