Simultaneous coherence enhancement of optical and microwave transitions in solid-state electronic spins

Abstract

Solid-state electronic spins are extensively studied in quantum information science, as their large magnetic moments offer fast operations for computing and communication, and high sensitivity for sensing. However, electronic spins are more sensitive to magnetic noise, but engineering of their spectroscopic properties, for example, using clock transitions and isotopic engineering, can yield remarkable spin coherence times, as for electronic spins in GaAs, donors in silicon and vacancy centres in diamond. Here we demonstrate simultaneously induced clock transitions for both microwave and optical domains in an isotopically purified Yb:YSiO crystal, reaching coherence times of greater than 100 μs and 1 ms in the optical and microwave domains, respectively. This effect is due to the highly anisotropic hyperfine interaction, which makes each electronic-nuclear state an entangled Bell state. Our results underline the potential of Yb:YSiO for quantum processing applications relying on both optical and spin manipulation, such as optical quantum memories, microwave-to-optical quantum transducers, and single-spin detection, while they should also be observable in a range of different materials with anisotropic hyperfine interactions.

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

“…The population relaxation lifetimes are significantly longer than in the 10 ppm doped 171 Yb 3+ :Y 2 SiO 5 sample used in Ref. [28], which indicates that the population relaxation is due to flipflops between ions in different hyperfine states [2,3,41]. A more detailed investigation of optical pumping and hyperfine flip-flop relaxation processes in this material will be presented elsewhere [42].…”

High-Cooperativity Coupling of a Rare-Earth Spin Ensemble to a Superconducting Resonator Using Yttrium Orthosilicate as a Substrate

“…These results demonstrate Y 2 SiO 5 is well-suited for superconducting devices, while also enabling an interaction with optically-accessible rare earth spins Further studies of this device include performing pulsed ESR measurements in the high-cooperativity regime and measuring coherence properties of the spin ensemble. The methods shown here are also applicable to other REIs in Y 2 SiO 5 , for example Er with its 1540 nm telecom band optical transition [7] and Yb which exhibits a large oscillator strength [34] and coherence-enhancing ZEFOZ and near-ZEFOZ transitions [32]. It may also prove interesting to study the suitability as a substrate of other crystalline hosts for REIs, such as yttrium aluminium garnet (YAG), yttrium lithium fluoride (YLF), yttrium orthovanadate (YVO 4 ), and calcium tungstate (CaWO 4 ).…”

Quantum information processing using frozen core Y3+ spins in Eu3+:Y2SiO5

“…Rare-earth solids have been identified as promising candidates for quantum memories in a series of recent demonstrations, including storage of quantum states with high efficiency [1][2][3] and long storage times [4][5][6], multimode storage [6][7][8] and entanglement storage [9,10]. In part, the interest in using rare earths for quantum memories is due to the long quantum coherence times observed for both optical and spin transitions in these systems [11][12][13][14][15][16][17][18][19].…”

“…As a result, the interaction of the rare-earth ions with the unavoidable nuclear spin bath continues to be a significant issue in maximizing the quantum coherence times and hence storage time of these systems. Having said this, long coherence times on both optical and spin transitions have been observed, which were achieved by applying techniques to decouple the rare-earth ions from the bath [13,14,[17][18][19][20]. The first technique commonly used is working at zero first order Zeeman (ZEFOZ) points: magnetic fields at which the transition has zero gradient in frequency with field and so is first-order insensitive to magnetic field fluctuations [13].…”