Interfacing superconducting qubits and telecom photons via a rare-earth-doped crystal

Phys Rev Lett. 2014 Aug 8;113(6):063603. doi: 10.1103/PhysRevLett.113.063603. Epub 2014 Aug 8.

Abstract

We propose a scheme to couple short single photon pulses to superconducting qubits. An optical photon is first absorbed into an inhomogeneously broadened rare-earth doped crystal using controlled reversible inhomogeneous broadening. The optical excitation is then mapped into a spin state using a series of π pulses and subsequently transferred to a superconducting qubit via a microwave cavity. To overcome the intrinsic and engineered inhomogeneous broadening of the optical and spin transitions in rare-earth doped crystals, we make use of a special transfer protocol using staggered π pulses. We predict total transfer efficiencies on the order of 90%.