Ion trap with in-vacuum high numerical aperture imaging for a dual-species modular quantum computer

Allison L Carter; Jameson O'Reilly; George Toh; Sagnik Saha; Mikhail Shalaev; Isabella Goetting; Christopher Monroe

doi:10.1063/5.0180732

Ion trap with in-vacuum high numerical aperture imaging for a dual-species modular quantum computer

Rev Sci Instrum. 2024 Mar 1;95(3):033201. doi: 10.1063/5.0180732.

Authors

Allison L Carter¹, Jameson O'Reilly^{1

2}, George Toh^{1

2}, Sagnik Saha^{1

2}, Mikhail Shalaev², Isabella Goetting², Christopher Monroe^{1

2}

Affiliations

¹ Joint Quantum Institute and Department of Physics, University of Maryland, College Park, Maryland 20742, USA.
² Duke Quantum Center, Department of Electrical and Computer Engineering, Department of Physics, Duke University, Durham, North Carolina 27701, USA.

PMID: 38477652
DOI: 10.1063/5.0180732

Abstract

Photonic interconnects between quantum systems will play a central role in both scalable quantum computing and quantum networking. Entanglement of remote qubits via photons has been demonstrated in many platforms; however, improving the rate of entanglement generation will be instrumental for integrating photonic links into modular quantum computers. We present an ion trap system that has the highest reported free-space photon collection efficiency for quantum networking. We use a pair of in-vacuum aspheric lenses, each with a numerical aperture of 0.8, to couple 10(1)% of the 493 nm photons emitted from a 138Ba+ ion into single-mode fibers. We also demonstrate that proximal effects of the lenses on the ion position and motion can be mitigated.