Optical Spin-Wave Storage in a Solid-State Hybridized Electron-Nuclear Spin Ensemble

Abstract

Solid-state impurity spins with optical control are currently investigated for quantum networks and repeaters. Among these, rare-earth-ion doped crystals are promising as quantum memories for light, with potentially long storage time, high multimode capacity, and high bandwidth. However, with spins there is often a tradeoff between bandwidth, which favors electronic spin, and memory time, which favors nuclear spins. Here, we present optical storage experiments using highly hybridized electron-nuclear hyperfine states in 171 Yb 3+ :Y2SiO5, where the hybridization can potentially offer both long storage time and high bandwidth. We reach a storage time of 1.2 ms and an optical storage bandwidth of 10 MHz that is currently only limited by the optical Rabi drive frequency. This constitutes the first optical storage experiment using spin states in any rare-earth ion with electronic spin. These results pave the way for rare-earth based quantum memories with high bandwidth, long storage time and high multimode capacity, a key resource for quantum repeaters.

Multifunctional on-chip storage at telecommunication wavelength for quantum networks

“…Improvements to the intrinsic quality factor of the resonator are required to reach the impedance matching condition. Creative solutions such as using clock transitions in 167 Er 3+ :Y 2 SiO 5 [37,43,44], which are less sensitive to superhyperfine coupling, or finding new crystal hosts for erbium ions [45] can be used to overcome the superhyperfine limit.…”

Multimode Storage of Quantum Microwave Fields in Electron Spins over 100 ms

“…Quantum memory as a matter-based information storage medium for itinerant qubits is a powerful ingredient in quantum technologies. In the optical domain [1][2][3], it underpins applications such as quantum repeaters. Quantum memories suitable for interfacing with superconducting quantum processors must operate in the microwave regime, which requires operation at millikelvin temperatures in a dilution refrigerator.…”

Coherence Time Extension by Large-Scale Optical Spin Polarization in a Rare-Earth Doped Crystal

“…A value of T 2;o up to approximately 800 μs was recorded, the longest reported for a paramagnetic RE at zero magnetic field and in the range to that of nonparamgnetic RE. Given the other favorable optical and spin properties of 171 Yb 3þ ∶Y 2 SiO 5 , our results open the way to new designs for broadband and efficient quantum memories for light [40] or optical to microwave transducers. We expect this process to be efficient in other rare-earth doped crystals and concentrated systems of optically addressable spins.…”

“…An analysis of the absorption spectrum, based on previously determined energies and branching ratios of transitions between ground-and excited-state spin levels, allowed us to accurately determine ground-state spin-level populations (see Refs. [32,40] and Supplemental Material [38] for details). This analysis shows that only 4% of the initial population is left in j4gi [ Fig.…”