Southwest Quantum Information and Technology

A nanophotonic platform integrating quantum memories and single qubits based on rare-earth ions

Presenting Author: Tian Zhong, IQIM, Caltech
Contributing Author(s): Jonathan Kindem, John Bartholomew, Jake Rochman, and Andrei Faraon

The integration of rare-earth ions in an on-chip photonic platform would enable quantum repeaters and scalable quantum networks. Here we demonstrate a nanophotonic platform consisting of yttrium vanadate (YVO) photonic crystal nanobeam resonators coupled to a spectrally dilute ensemble of Nd ions. The cavity acts as a memory when prepared with spectral hole burning, meanwhile it permits addressing of single ions. For quantum memory, atomic frequency comb (AFC) protocol was implemented in a Nd:YVO nanocavity cooled to 475 mk. We measure an efficiency at 2% at a storage time of ~100 ns with an efficient WSi superconducting nanowire detector (SNSPD). The small mode volume of the cavity results in a peak atomic spectral density of <10 ions per homogeneous linewidth, suitable for probing single ions when detuned. The high-cooperativity coupling of a single ion yields a strong signature (20%) in the cavity reflection spectrum. We estimate a signal-to-noise ratio exceeding 10 for addressing a single Nd ion. This, combines with the AFC memory, constitutes a promising platform for preparation, storage and detection of rare-earth qubits on the same chip.

(Session 13 : Saturday from 4:15pm - 4:45pm)