Quantum computing with graphene plasmons

Author(s)
I. Alonso Calafell, J. D. Cox, M. Radonjic, J. R. M. Saavedra, F. J. Garcia de Abajo, L. A. Rozema, P. Walther
Abstract

Among the various approaches to quantum computing, all-optical architectures are especially promising due to the robustness and mobility of single photons. However, the creation of the two-photon quantum logic gates required for universal quantum computing remains a challenge. Here we propose a universal two-qubit quantum logic gate, where qubits are encoded in surface plasmons in graphene nanostructures, that exploits graphene's strong third-order nonlinearity and long plasmon lifetimes to enable single-photon-level interactions. In particular, we utilize strong two-plasmon absorption in graphene nanoribbons, which can greatly exceed single-plasmon absorption to create a "square-root-of-swap" that is protected by the quantum Zeno effect against evolution into undesired failure modes. Our gate does not require any cryogenic or vacuum technology, has a footprint of a few hundred nanometers, and reaches fidelities and success rates well above the fault-tolerance threshold, suggesting that graphene plasmonics offers a route towards scalable quantum technologies.

Organisation(s)
Quantum Optics, Quantum Nanophysics and Quantum Information
External organisation(s)
Barcelona Institute of Science & Technology, Institució Catalana de Recerca i Estudis Avançats (ICREA), University of Belgrade
Journal
npj Quantum Information
Volume
5
No. of pages
7
ISSN
2056-6387
DOI
https://doi.org/10.1038/s41534-019-0150-2
Publication date
05-2019
Peer reviewed
Yes
Austrian Fields of Science 2012
103025 Quantum mechanics, 103021 Optics
Keywords
Portal url
https://ucris.univie.ac.at/portal/en/publications/quantum-computing-with-graphene-plasmons(b832a03e-de86-4ea3-9f34-ca88e5455e51).html