30 research outputs found
Quantum State Engineering using Single Nuclear Spin Qubit of Optically Manipulated Ytterbium Atom
A single Yb atom is loaded into a high-finesse optical cavity with a moving
lattice, and its nuclear spin state is manipulated using a nuclear magnetic
resonance technique. A highly reliable quantum state control with fidelity and
purity greater than 0.98 and 0.96, respectively, is confirmed by the full
quantum state tomography; a projective measurement with high speed (500us) and
high efficiency (0.98) is accomplished using the cavity QED technique. Because
a hyperfine coupling is induced only when the projective measurement is
operational, the long coherence times (T_1 = 0.49 s and T_2 = 0.10 s) are
maintained. Our technique can be applied for implementing a scalable one-way
quantum computation with a cluster state in an optical lattice.Comment: 4 figure
Faraday Rotation with Single Nuclear Spin Qubit in a High-Finesse Optical Cavity
When an off-resonant light field is coupled with atomic spins, its
polarization can rotate depending on the direction of the spins via a Faraday
rotation which has been used for monitoring and controlling the atomic spins.
We observed Faraday rotation by an angle of more than 10 degrees for a single
1/2 nuclear spin of 171Yb atom in a high-finesse optical cavity. By employing
the coupling between the single nuclear spin and a photon, we have also
demonstrated that the spin can be projected or weakly measured through the
projection of the transmitted single ancillary photon.Comment: 6 pages, 6 figure