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arXiv:2302.07791 · Science

Splitting phonons: Building a platform for linear mechanical quantum computing

Hong Wei Qiao, Étienne Dumur, Gustav Andersson, Haoxiong Yan, M.-H. Chou, Joel Grebel, Christopher R. Conner, Yash J. Joshi, Jacob M. Miller, Rhys G. Povey, Xuntao Wu, Andrew N. Cleland

Published Jun 8, 2023• 96 citations
arXivHTMLPDF

Abstract

Linear optical quantum computing provides a desirable approach to quantum computing, with only a short list of required computational elements. The similarity between photons and phonons points to the interesting potential for linear mechanical quantum computing using phonons in place of photons. Although single-phonon sources and detectors have been demonstrated, a phononic beam splitter element remains an outstanding requirement. Here we demonstrate such an element, using two superconducting qubits to fully characterize a beam splitter with single phonons. We further use the beam splitter to demonstrate two-phonon interference, a requirement for two-qubit gates in linear computing. This advances a new solid-state system for implementing linear quantum computing, further providing straightforward conversion between itinerant phonons and superconducting qubits.

DOI
10.1126/science.adg8715

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Linear optical quantum computing provides a desirable approach to quantum computing, with only a short list of required computational elements. The similarity between photons and phonons points to the interesting potential for linear mechanical quantum computing using phonons in place of photons. Although single-phonon sources and detectors have been demonstrated, a phononic beam splitter element remains an outstanding requirement. Here we demonstrate such an element, using two superconducting qubits to fully characterize a beam splitter with single phonons. We further use the beam splitter to demonstrate two-phonon interference, a requirement for two-qubit gates in linear computing. This advances a new solid-state system for implementing linear quantum computing, further providing straightforward conversion between itinerant phonons and superconducting qubits.
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The initial proposal for scalable optical quantum computing required single photon sources, linear optical elements such as beamsplitters and phaseshifters, and photon detection. Here, we demonstrate a two qubit gate using indistinguishable photons from a quantum dot in a pillar microcavity. As the emitter, the optical circuitry, and the detectors are all semiconductor, this is a promising approach towards creating a fully integrated device for scalable quantum computing. © 2012 American Institute of Physics.
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