We introduce the `displacemon' electromechanical architecture that comprises a vibrating nanobeam, e.g. a carbon nanotube, flux coupled to a superconducting qubit. This platform can achieve strong and even ultrastrong coupling enabling a variety of quantum protocols. We use this system to describe a protocol for generating and measuring quantum interference between two trajectories of a nanomechanical resonator. The scheme uses a sequence of qubit manipulations and measurements to cool the resonator, apply an effective diffraction grating, and measure the resulting interference pattern. We simulate the protocol for a realistic system consisting of a vibrating carbon nanotube acting as a junction in a superconducting qubit, and we demonstrate the feasibility of generating a spatially distinct quantum superposition state of motion containing more than 106 nucleons.
@article{arxiv.1710.01920,
title = {Displacemon electromechanics: how to detect quantum interference in a nanomechanical resonator},
author = {Kiran E. Khosla and Michael R. Vanner and Natalia Ares and Edward A. Laird},
journal= {arXiv preprint arXiv:1710.01920},
year = {2020}
}