Coherent properties of single rare-earth spin qubits

Abstract

Rare-earth-doped crystals are excellent hardware for quantum storage of photons. Additional functionality of these materials is added by their waveguiding properties allowing for on-chip photonic networks. However, detection and coherent properties of rare-earth single-spin qubits have not been demonstrated so far. Here we present experimental results on high-fidelity optical initialization, effcient coherent manipulation and optical readout of a single-electron spin of Ce 3+ ion in a yttrium aluminium garnet crystal. Under dynamic decoupling, spin coherence lifetime reaches T 2 =2â €‰ms and is almost limited by the measured spin-lattice relaxation time T 1 =4.5â €‰ms. Strong hyperfine coupling to aluminium nuclear spins suggests that cerium electron spins can be exploited as an interface between photons and long-lived nuclear spin memory. Combined with high brightness of Ce 3+ emission and a possibility of creating photonic circuits out of the host material, this makes cerium spins an interesting option for integrated quantum photonics. © 2014 Macmillan Publishers Limited. All rights reserved.