Efficient Collection of Single Photons Emitted from a Trapped Ion into a Single Mode Fiber for Scalable Quantum Information Processing

TL;DR

This paper explores methods to significantly improve the efficiency of collecting single photons emitted from trapped ions into single mode fibers, which is crucial for scalable quantum information processing.

Contribution

It introduces analytic strategies to enhance photon collection efficiency from trapped ions, achieving over 30% with an optical cavity and over 15% with high NA optics.

Findings

Achieved over 30% fiber coupling efficiency with an optical cavity.

Demonstrated potential for over 15% collection efficiency using high numerical aperture optics.

Provided analytic methods applicable to various ion and neutral atom systems.

Abstract

Interference and coincidence detection of two photons emitted by two remote ions can lead to an entangled state which is a critical resource for scalable quantum information processing. Currently, the success probabilities of experimental realizations of this protocol are mainly limited by low coupling efficiency of a photon emitted by an ion into a single mode fiber. Here, we consider two strategies to enhance the collection probability of a photon emitted from a trapped Yb ion, using analytic methods that can be easily applied to other types of ion or neutral atoms. Our analysis shows that we can achieve fiber coupling efficiency of over 30% with an optical cavity made of a flat fiber tip and a spherical mirror. We also investigate ways to increase the fiber coupling efficiency using high numerical aperture optics, and show that collection probability of over 15% is possible with proper control of aberration.