Rekishu Yamazaki

Submicron spatial modulation of an interatomic interaction in a Bose-Einstein condensate.

We demonstrate submicron spatial control of interatomic interactions in a Bose-Einstein condensate of ytterbium (Yb). A pulsed optical standing wave, tuned near an optical Feshbach resonance, varies the s-wave scattering length continuously across the standing wave pattern. The modulated mean-field energy with a spatial period every 278 nm is monitored by a diffraction pattern in a time-of-flight image. We observe a wide scattering length control of up to 250 nm. The demonstrated spatial modulation of the scattering length proves that high resolution control of atomic interactions is possible.

Realization of a SU(2) X SU(6) System of Fermions in a Cold Atomic Gas

We report the realization of a novel degenerate Fermi mixture with an SU(2)×SU(6) symmetry in a cold atomic gas. We successfully cool the mixture of the two fermionic isotopes of ytterbium Yb with the nuclear spin I = 1/2 and Yb with I = 5/2 below the Fermi temperature TF as 0.46TF for Yb and 0.54TF for Yb. The same scattering lengths for different spin components make this mixture featured with the novel SU(2)×SU(6) symmetry. The nuclear spin components are separately imaged by exploiting an optical Stern-Gerlach effect. In addition, the mixture is loaded into a 3D optical lattice to implement the SU(2)×SU(6) Hubbard model. This mixture will open the door to the study of novel quantum phases such as a spinor Bardeen-Cooper-Schrieffer-like fermionic superfluid.

An SU(6) Mott insulator of an atomic Fermi gas realized by large-spin Pomeranchuk cooling

A multicomponent gas of ytterbium atoms accommodates more entropy in its spin degrees of freedom than does its two-component analogue, leading to a lower effective temperature, and an easy route for cooling ultracold fermions towards a Mott-insulating state.

Observation of ap-wave optical Feshbach resonance

We demonstrate a p

Quantum gate using qubit states separated by terahertz

-wave optical Feshbach resonance (OFR) using purely long-range molecular states of a fermionic isotope of ytterbium ^{171}Yb, following the proposition made by K. Goyal et al. [Phys. Rev. A 82, 062704 (2010)]. The p-wave OFR is clearly observed as a modification of a photoassociation rate for atomic ensembles at about 5 micro-Kelvins. A scattering phase shift variation of \delta \eta=0.022 rad is observed with an atom loss rate coefficient K=28.0*10^{-12} cm^3/s.

One- and two-photon ionization cross sections of the laser-excited 6s6p1 P1 state of barium

A two-qubit quantum gate is realized using electronically excited states in a single ion with an energy separation on the order of a terahertz times the Planck constant as a qubit. Two phase-locked lasers are used to excite a stimulated Raman transition between two metastable states

Phase-locked laser system for a metastable states qubit in 40 Ca+.

{D}_{3/2}

ULTRACOLD YTTERBIUM ATOMS IN OPTICAL LATTICES

and

Strong variation of the phase lag in the vicinity of autoionizing resonances

{D}_{5/2}

Interaction and filling-induced quantum phases of dual Mott insulators of bosons and fermions

separated by