Shinsuke Haze

Experimental realization of a quantum phase transition of polaritonic excitations.

We report an experimental realization of the Jaynes-Cummings-Hubbard model using the internal and radial phonon states of two trapped ions. An adiabatic transfer corresponding to a quantum phase transition from a localized insulator ground state to a delocalized superfluid (SF) ground state is demonstrated. The SF phase of polaritonic excitations characteristic of the interconnected Jaynes-Cummings (JC) system is experimentally explored, where a polaritonic excitation refers to a combination of an atomic excitation and a phonon interchanged via a JC coupling.

Realization of holonomic single-qubit operations

Universal single-qubit operations based on purely geometric phase factors in adiabatic processes are demonstrated by utilizing a four-level system in a trapped single

Charge-exchange collisions between ultracold fermionic lithium atoms and calcium ions

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Observation of elastic collisions between lithium atoms and calcium ions

Ca

Generation of Dicke states using adiabatic passage

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Quantum gate using qubit states separated by terahertz

ion connected by three oscillating fields. Robustness against parameter variations is studied. The scheme demonstrated here can be employed as a building block for large-scale holonomic quantum computations, which may be useful for large qubit systems with statistical variations in system parameters.

Note: Auto-relock system for a bow-tie cavity for second harmonic generation

Charge exchange collisions between ultracold fermionic 6Li atoms and 40Ca+ ions are observed in the mK temperature range. The reaction product of the charge exchange collision is identified via mass spectrometry during which the motion of the ions is excited parametrically. The cross-sections of the charge exchange collisions between 6Li atoms in the ground state and 40Ca+ ions in the ground and metastable excited states are determined. Investigation of the inelastic collision characteristics in the atom-ion mixture is an important step toward ultracold chemistry based on ultracold atoms and ions.

Quantum simulation of the Jaynes-Cummings-Hubbard model using trapped ions

We observed elastic collisions between laser-cooled fermionic lithium atoms and calcium ions at the energy range from 100 mK to 3 K. Lithium atoms in an optical-dipole trap were transported to the center of the ion trap using an optical-tweezer technique, and a spatial overlap of the atoms and ions was realized in order to observe the atom-ion interactions. The elastic-scattering rate was determined from the decay of atoms due to elastic collisions with ions. The collision-energy dependence of the elastic-scattering cross section was consistent with semiclassical collision theory.

Realization of robust single-qubit operations with purely geometric phase factors

Entangled states of two ions are realized by using an adiabatic process. Based on the proposal by Linington and Vitanov [Phys. Rev. A 77, 010302 (2008)], we have generated Dicke states in optical qubits of two

Realization of Fast Rabi Oscillations in Radio Frequency Magnetic Resonance of Ground Zeeman States of 40Ca

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