Long spin coherence times in the ground state and in an optically excited state of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mmultiscripts><mml:mi>Er</mml:mi><mml:none/><mml:mrow><mml:mn>3</mml:mn><mml:mo>+</mml:mo></mml:mrow><mml:mprescripts/><mml:none/><mml:mn>167</mml:mn></mml:mmultiscripts><mml:mo>:</mml:mo><mml:msub><mml:mi mathvariant="normal">Y</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi>SiO</mml:mi><mml:mn>5</mml:mn></mml:msub></mml:mrow></mml:math> at zero magnetic field

Abstract

Although superconducting qubits are one of the most promising systems for quantum information applications, a separate interface is required to allow for information distribution through optical links. Here, the authors investigate the suitability of ${}^{167}$Er${}^{3+}$:Y${}_{2}$SiO${}_{5}$ as a microwave-to-optical memory interface. This material holds considerable promise as it has an optical transition in the telecommunication band. The authors identify hyperfine transitions with long coherence times without an external magnetic field, which are suitable for interfacing with superconducting qubit systems.

Topics & Concepts