Sensing Aharonov-Bohm Phase Using a Multiply-Orbiting-Ion Interferometer.

Interferometers, which are built using spatially propagating light or matter waves, are commonly used to measure physical quantities. These measurements are made possible by exploiting the interference between waves traveling along different paths. This study introduces a novel approach to sensing of the Aharonov-Bohm phase, an ion matter-wave interferometer operating within a two-dimensional rotational trajectory in a trap potential.

Three-Dimensional Matter-Wave Interferometry of a Trapped Single Ion.

We report on a demonstration of Ramsey interferometry by three-dimensional motion with a trapped ^{171}Yb^{+} ion. We applied a momentum kick to the ion in a direction diagonal to the trap axes to initiate three-dimensional motion using a mode-locked pulse laser. The interference signal was analyzed theoretically to demonstrate three-dimensional matter-wave interference.

Quantum Walks of a Phonon in Trapped Ions.

We report the observation of the quantum walks of a phonon, a vibrational quantum, in a trapped-ion crystal. By employing the capability to prepare and observe the localized wave packet of a phonon, the propagation of a single radial local phonon in a four-ion linear crystal is observed with single-site resolution. The results show an agreement with numerical calculations, indicating the predictability and reproducibility of the phonon system.

Scaling Law for Three-Body Collisions of Identical Fermions with p-Wave Interactions.

We experimentally confirmed the threshold behavior and scattering length scaling law of the three-body loss coefficients in an ultracold spin-polarized gas of ^{6}Li atoms near a p-wave Feshbach resonance. We measured the three-body loss coefficients as functions of temperature and scattering volume, and we found that the threshold law and the scattering length scaling law hold in limited temperature and magnetic field regions. We also found that the breakdown of the scaling laws is due to the emergence of the effective-range term.

Cooling Dynamics of a Single Trapped Ion via Elastic Collisions with Small-Mass Atoms.

We demonstrated sympathetic cooling of a single ion in a buffer gas of ultracold atoms with small mass. Efficient collisional cooling was realized by suppressing collision-induced heating. We attempt to explain the experimental results with a simple rate equation model and provide a quantitative discussion of the cooling efficiency per collision.

A self-injected, diode-pumped, solid-state ring laser for laser cooling of Li atoms.

We have constructed a solid-state light source for experiments with laser cooled lithium atoms based on a Nd:YVO4 ring laser with second-harmonic generation. Unidirectional lasing, an improved mode selection, and a high output power of the ring laser were achieved by weak coupling to an external cavity which contained the lossy elements required for single frequency operation. Continuous frequency tuning is accomplished by controlling two piezoelectric transducers (PZTs) in the internal and the external cavities simultaneously.

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

This Note reports on the implementation of an automatic relocking system for a bow-tie cavity for second harmonic generation to produce an ultra-violet laser source. The system is based on a sample-and-hold technique for controlling the cavity length using simple servo electronics. Long-term stabilization of the cavity output power is successfully achieved, which makes this system suitable for designing stable atomic physics experiments.

Measurement of an Efimov trimer binding energy in a three-component mixture of 6Li.

The binding energy of an Efimov trimer state was precisely determined via radio-frequency association. It is found that the measurement results shift significantly with temperature, but that the shift becomes negligible at the lowest temperature in our experiment. The shift-free part of the trimer binding energy reveals a significant deviation from the nonuniversal theory prediction based on a three-body parameter with a monotonic binding-energy dependence.

Nonuniversal Efimov atom-dimer resonances in a three-component mixture of 6Li.

We observed an enhanced atom-dimer loss due to the existence of Efimov states in a three-component mixture of 6Li atoms. We measured the magnetic-field dependence of the atom-dimer loss in the mixture of atoms in state |1> and dimers formed in states |2> and |3>, and found two peaks corresponding to the degeneracy points of the energy levels of |23> dimers and the ground and first excited Efimov trimers. We found that the locations of these peaks disagree with universal theory predictions, in a way that cannot be explained by nonuniversal two-body properties.

Measurement of universal thermodynamic functions for a unitary Fermi gas.

Thermodynamic properties of matter generally depend on the details of interactions between its constituent parts. However, in a unitary Fermi gas where the scattering length diverges, thermodynamics is determined through universal functions that depend only on the particle density and temperature. By using only the general form of the equation of state and the equation of force balance, we measured the local internal energy of the trapped gas as a function of these parameters.

Critical temperature and condensate fraction of a fermion pair condensate.

We report on measurements of the critical temperature and the temperature dependence of the condensate fraction for a fermion pair condensate of 6Li atoms. Bragg spectroscopy is employed to determine the critical temperature and the condensate fraction after a fast magnetic field ramp to the molecular side of the Feshbach resonance. Our measurements reveal evidence of level off of the critical temperature and limiting behavior of condensate fraction near the unitarity limit.

Collisional properties of p-wave Feshbach molecules.

We have observed p-wave Feshbach molecules for all three combinations of the two lowest hyperfine spin states of 6Li. By creating a pure molecular sample in an optical trap, we measured the inelastic collision rates of p-wave molecules. We have also measured the elastic collision rate from the thermalization rate of a breathing mode which was excited spontaneously upon molecular formation.

Heavy photon states in photonic chains of resonantly coupled cavities with supermonodispersive microspheres.

We propose and demonstrate a "bottom-up" approach to constructing photonic structures for photon manipulation. Supermonodispersive polymer microspheres are used as building blocks and a size uniformity better than 0.05% could be obtained by sorting the spheres using spectroscopic methods.

Photonic molecule lasing.

Lasing at resonantly coupled whispering-gallery mode frequencies is observed in photonic molecules consisting of bispheres of 4.2 and 5.1 microm in diameter placed in a silicon V-groove.

Recoil-limited laser cooling of 87Sr atoms near the Fermi temperature.

A dynamic magneto-optical trap, which relies on the rapid randomization of population in Zeeman substates, has been demonstrated for fermionic strontium atoms on the 1S0-3P1 intercombination transition. The obtained sample, 1x10(6) atoms at a temperature of 2 microK in the trap, was further Doppler cooled and polarized in a far-off resonant optical lattice to achieve 2 times the Fermi temperature.