Telecom Networking with a Diamond Quantum Memory
Eric Bersin, Madison Sutula, Yan Qi Huan, Aziza Suleymanzade, Daniel Assumpção, Yan-Cheng Wei, Pieter-Jan Stas, Can M. Knaut, Erik Knall, Carsten Langrock, Neil Sinclair, Ryan P. Murphy, Ralf Riedinger, Matthew Yeh, C. J. Xin, Saumil Bandyopadhyay, Denis D. Sukachev, Bartholomeus Machielse, David Levonian, Mihir K. Bhaskar, Scott A. Hamilton, Hongkun Park, Marko Lončar, M. M. Fejer, P. Ben Dixon, Dirk Englund, Mikhail D. Lukin
Abstract
Practical quantum networks require interfacing quantum memories with existing channels and systems that operate in the telecom band. Here we demonstrate low-noise, bidirectional quantum frequency conversion that enables a solid-state quantum memory to directly interface with telecom-band systems. In particular, we demonstrate conversion of visible-band single photons emitted from a silicon-vacancy (<a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"><a:mi>Si</a:mi></a:math><d:math xmlns:d="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"><d:mi>V</d:mi></d:math>) center in diamond to the telecom <g:math xmlns:g="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"><g:mrow><g:mrow><g:mi mathvariant="normal">O</g:mi></g:mrow></g:mrow></g:math> band, maintaining low noise (<k:math xmlns:k="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"><k:msup><k:mi>g</k:mi><k:mn>2</k:mn></k:msup><k:mo stretchy="false">(</k:mo><k:mn>0</k:mn><k:mo stretchy="false">)</k:mo><k:mo><</k:mo><k:mn>0.1</k:mn></k:math>) and high indistinguishability (<p:math xmlns:p="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"><p:mi>V</p:mi><p:mo>=</p:mo><p:mn>89</p:mn><p:mo>±</p:mo><p:mn>8</p:mn><p:mi mathvariant="normal">%</p:mi></p:math>). We further demonstrate the utility of this system for quantum networking by converting telecom-band time-bin pulses, sent across a lossy and noisy 50-km deployed fiber link, to the visible band and entangling them with a diamond quantum memory with fidelity <t:math xmlns:t="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"><t:mrow><t:mi mathvariant="script">F</t:mi></t:mrow><t:mo>≥</t:mo><t:mn>87</t:mn><t:mo>±</t:mo><t:mn>2.5</t:mn><t:mi mathvariant="normal">%</t:mi></t:math>. These results demonstrate the viability of <y:math xmlns:y="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"><y:mi>Si</y:mi></y:math><bb:math xmlns:bb="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"><bb:mi>V</bb:mi></bb:math> quantum memories integrated with telecom-band systems for scalable quantum networking applications. Published by the American Physical Society 2024