Ultracold polar molecules as qudits

Sawant, Rahul; Blackmore, Jacob; Gregory, Philip; Mur-Petit, Jordi; Jaksch, Dieter; Aldegunde, Jesus; Hutson, Jeremy M.; Tarbutt, Mike; Cornish, S. L.

Abstract

We discuss how the internal structure of ultracold molecules, trapped in the motional ground state of optical tweezers, can be used to implement qudits. We explore the rotational, fine and hyperfine structure of $^{40}$Ca$^{19}$F and $^{87}$Rb$^{133}$Cs, which are examples of molecules with $^2\Sigma$ and $^1\Sigma$ electronic ground states, respectively. In each case we identify a subset of levels within a single rotational manifold suitable to implement a 4-level qudit. Quantum gates can be implemented using two-photon microwave transitions via levels in a neighboring rotational manifold. We discuss limitations to the usefulness of molecular qudits, arising from off-resonant excitation and decoherence. As an example, we present a protocol for using a molecular qudit of dimension $d=4$ to perform the Deutsch algorithm.

Citation

Sawant, R., Blackmore, J., Gregory, P., Mur-Petit, J., Jaksch, D., Aldegunde, J., Hutson, J. M., Tarbutt, M., & Cornish, S. L. (2020). Ultracold polar molecules as qudits. New Journal of Physics, 22, Article 013027. https://doi.org/10.1088/1367-2630/ab60f4

• Journal Article Type: Article
• Acceptance Date: Dec 11, 2019
• Online Publication Date: Jan 20, 2020
• Publication Date: Jan 31, 2020
• Deposit Date: Dec 12, 2019
• Publicly Available Date: Jan 21, 2020
• Journal: New Journal of Physics
• Publisher: IOP Publishing
• Peer Reviewed: Peer Reviewed
• Volume: 22
• Article Number: 013027
• DOI: https://doi.org/10.1088/1367-2630/ab60f4
• Public URL: https://durham-repository.worktribe.com/output/1281013
• Related Public URLs: https://arxiv.org/abs/1909.07484