title: Spin-orbit qubits of rare-earth-metal ions in axially symmetric crystal fields.
abstract: Contrary to the well-known spin qubits, rare-earth-metal qubits are characterized by a strong influence of crystal field due to large spin-orbit coupling. At low temperature and in the presence of resonance microwaves, it is the magnetic moment of the crystal-field ground state which nutates (for several micros) and the Rabi frequency Omega(R) is anisotropic. Here, we present a study of the variations of Omega(R)(H(0)) with the magnitude and direction of the static magnetic field H(0) for the odd 167Er isotope in a single crystal CaWO(4):Er(3+). The hyperfine interactions split the Omega(R)(H(0)) curve into eight different curves which are fitted numerically and described analytically. These "spin-orbit qubits" should allow detailed studies of decoherence mechanisms which become relevant at high temperature and open new ways for qubit addressing using properly oriented magnetic fields.
authors.affiliation: IM2NP, CNRS and Université Paul Cézanne, Avenue Escadrille Normandie Niemen-Case 142-13397 Marseille Cedex 20, France.
authors.forename: S
authors.initials: S
authors.lastname: Bertaina
authors.forename: J H
authors.initials: JH
authors.lastname: Shim
authors.forename: S
authors.initials: S
authors.lastname: Gambarelli
authors.forename: B Z
authors.initials: BZ
authors.lastname: Malkin
authors.forename: B
authors.initials: B
authors.lastname: Barbara