Mesoscopic mechanical superpositions by gluing individual quantum systems

Abstract

We propose a protocol for preparing mechanical Schrödinger kittens -- mesoscopic quantum superpositions of coherent motional states of an optically levitated nanoparticle -- by adhering single electron time-bin states to its surface. Over short protocol timescales, coherence of the mesoscopic superposition survives the dominant decoherence mechanisms afflicting levitated systems, and can be observed by varying the phase of the time-bin electrons. Interference fringes can be detected with real-time, near-Heisenberg limited interferometry of photons scattered from the particle. This approach eliminates the need for coherent state expansion, dark potentials, and particle release-and-recapture mechanisms, providing a new route to test quantum mechanics in unprecedented scales.