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Updated: May 28, 2025

Gradient Echo Quantum Memory in Warm Atomic Vapor
Published on: November 11, 2013
Coherent Control of a Long-Lived Nuclear Memory Spin in a Germanium-Vacancy Multi-Qubit Node
Nick Grimm1, Katharina Senkalla1, Philipp J Vetter1
1Ulm University, Institute for Quantum Optics, Albert-Einstein-Allee 11, 89081 Ulm, Germany.
Abstract:
The ability to process and store information on surrounding nuclear spins is a major requirement for group-IV color center-based repeater nodes. We demonstrate coherent control of a ^{13}C nuclear spin strongly coupled to a negatively charged germanium-vacancy center in diamond with coherence times beyond 2.5 s at mK temperatures, which is the longest reported for group-IV defects. Detailed analysis allows us to model the system's dynamics, extract the coupling parameters, and characterize noise. We estimate an achievable memory time of 18.1 s with heating limitations considered, paving the way to successful applications as a quantum repeater node.
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