Measurement-based preparation of multimode mechanical states

Nanomechanical resonators are a key tool for future quantum technologies, such as quantum force sensors and interfaces, and for studies of macroscopic quantum physics. The ability to prepare room temperature nonclassical states is a major outstanding challenge. It has been suggested that this could be achieved using a fast continuous measurement to break the usual symmetry between position and momentum. Here, we demonstrate this symmetry breaking and use it to prepare a thermally squeezed mechanical state. Our experiments take advantage of collective measurements on multiple mechanical modes, which we show can increase the measurement speed and improve state preparation. Theoretically, we show that this result extends to the quantum regime, relaxing the requirements to generate nonclassical states. We predict that multimode conditioning can enable room temperature quantum squeezing with existing technology. Our work paves the way toward room temperature quantum nanomechanical devices and toward their application in quantum technology and fundamental science.

Automated summary

Nanomechanical resonators are important tools for studying quantum technology and macroscopic quantum physics. Preparing nonclassical states at room temperature is a challenge. This study demonstrates the preparation of a thermally squeezed mechanical state by breaking the symmetry between position and momentum using fast continuous measurement. Collective measurements on multiple mechanical modes are utilized to increase measurement speed and improve state preparation. The results suggest that existing technology can enable room temperature quantum squeezing through multimode conditioning. This work paves the way for quantum nanomechanical devices at room temperature and their applications in quantum technology and fundamental science.