Quantum Photonic Devices

Integration of optically active neodymium ions in niobium devices (Nd:Nb): quantum memory for hybrid quantum entangled systems

Osama M. Nayfeh, Patrick C. Sims, Brad Liu, Saurabh Sharma, Carlos M. Torres, Lance Lerum, Mohammed Fahem, Sanja Zlatanovic, Vincent Dinh, Nenad Djapic, David Chao, Dave Rees, Britanny Lynn, Brian Higa, John Moore, Aaron Upchurch, John Cothern, Mark Tukeman, Ripan Barua, Bradley D. Davidson, Ayax D. Ramirez, Vikas Anant, Gregory S. Kanter

Published Aug 29, 2017• 0 citations

Publisher

Abstract

Optically active rare-earth Neodymium (Nd) ions are integrated in Niobium (Nb) thin films forming a new quantum memory device (Nd:Nb) targeting long-lived coherence times and multi-functionality enabled by both spin and photon storage properties. Nb is implanted with Nd spanning 10-60 keV energy and 1013-1014 cm-2 dose producing a 1- 3% Nd:Nb concentration as confirmed by energy-dispersive X-ray spectroscopy. Scanning confocal photoluminescence (PL) at 785 nm excitation are made and sharp emission peaks from the 4F3/2 -< 4I11/2 Nd3+ transition at 1064-1070 nm are examined. In contrast, un-implanted Nb is void of any peaks. Line-shapes at room temperature are fit with Lorentzian profiles with line-widths of 4-5 nm and 1.3 THz bandwidth and the impacts of hyperfine splitting via the metallic crystal potential are apparent and the co-contribution of implant induced defects. With increasing Nd from 1% to 3%, there is a 0.3 nm red shift and increased broadening to a 4.8 nm linewidth. Nd:Nb is photoconductive and responds strongly to applied fields. Furthermore, optically detected magnetic resonance (ODMR) measurements are presented spanning near-infrared telecom band. The modulation of the emission intensity with magnetic field and microwave power by integration of these magnetic Kramer type Nd ions is quantified along with spin echoes under pulsed microwave π-π/2 excitation. A hybrid system architecture is proposed using spin and photon quantum information storage with the nuclear and electron states of the Nd3+ and neighboring Nb atoms that can couple qubit states to hyperfine 7/2 spin states of Nd:Nb and onto NIR optical levels excitable with entangled single photons, thus enabling implementation of computing and networking/internet protocols in a single platform.

DOI: 10.1117/12.2273012

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