title: Anisotropic rare-earth spin ensemble strongly coupled to a superconducting resonator.
abstract: Interfacing photonic and solid-state qubits within a hybrid quantum architecture offers a promising route towards large scale distributed quantum computing. Ideal candidates for coherent qubit interconversion are optically active spins, magnetically coupled to a superconducting resonator. We report on an on-chip cavity QED experiment with magnetically anisotropic Er(3+)∶Y2SiO5 crystals and demonstrate collective strong coupling of rare-earth spins to a lumped element resonator. Moreover, the electron spin resonance and relaxation dynamics of the erbium spins are detected via direct microwave absorption, without the aid of a cavity.
authors.affiliation: Physikalisches Institut, Karlsruhe Institute of Technology, D-76128 Karlsruhe, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Probst
authors.affiliation: Physikalisches Institut, Karlsruhe Institute of Technology, D-76128 Karlsruhe, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Rotzinger
authors.affiliation: Institut für Mikro- und Nanoelektronische Systeme, Karlsruhe Institute of Technology, D-76189 Karlsruhe, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Wünsch
authors.affiliation: Physikalisches Institut, Karlsruhe Institute of Technology, D-76128 Karlsruhe, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Jung
authors.affiliation: Physikalisches Institut, Karlsruhe Institute of Technology, D-76128 Karlsruhe, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Jerger
authors.affiliation: Institut für Mikro- und Nanoelektronische Systeme, Karlsruhe Institute of Technology, D-76189 Karlsruhe, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Siegel
authors.affiliation: Physikalisches Institut, Karlsruhe Institute of Technology, D-76128 Karlsruhe, Germany.
authors.forename: A V
authors.initials: AV
authors.lastname: Ustinov
authors.affiliation: Physikalisches Institut, Karlsruhe Institute of Technology, D-76128 Karlsruhe, Germany.
authors.forename: P A
authors.initials: PA
authors.lastname: Bushev