제원호 교수

The radiative decay of Cs atoms excited into the 5${\mathrm{D}}_{5/2}$ level and passing between two metallic mirrors spaced by a 1.1-\ensuremath{\mu}m gap is observed to depend upon their angular momentum. Spontaneous emission at a wavelength of 3.49 \ensuremath{\mu}m is suppressed for the substates with maximum angular momentum normal to the mirrors, which survive without substantial decay during \ensuremath{\sim}13 natural lifetimes. The radiation rate is modified by application of a magnetic

Friction in an ambient condition involves highly nonlinear interactions of capillary force, induced by the capillary-condensed water nanobridges between contact or noncontact asperities of two sliding surfaces. Since the real contact area of sliding solids is much smaller than the apparent contact area, the nanobridges formed on the distant asperities can contribute significantly to the overall friction. Therefore, it is essential to understand how the water nanobridges mediate the 'noncontact'

We present a novel method for investigating a nanometric cluster of water molecules, which includes the formation and manipulation of nanometric water, and the measurement of its mechanical properties. The atomic force microscope based on the quartz tuning-fork sensor is employed to form and manipulate the nanometric water, and the theoretical tool of amplitude-modulation atomic force microscopy is used to obtain the elasticity, viscosity and dissipation energy of it. With high vertical resoluti

Supplementary data are available at Bioinformatics online.

Electric-field-induced low-volume liquid ejection under ambient conditions was realized at a low bias potential of 12 V via a nanopipette (aperture diameter of 30 nm) combined with a non-contact, distance-regulated (within 10 nm) quartz tuning fork-atomic force microscope. A capillary-condensed water meniscus, spontaneously formed in the tip-substrate nanogap, reduces the ejection barrier by four orders of magnitude, facilitating nanoliquid ejection and subsequent liquid transport/dispersion ont

We calculate the QED energy-level shifts of an atom between two perfectly conducting mirrors in perturbation theory. We separate the contributions of vacuum fluctuation and self-radiation reaction to the shifts between two mirrors. This provides unambiguous assignment of each effect on the cavity-induced shifts, and allows reinterpretation of previously derived results. In particular, we are able to identify the Casimir interaction as a pure effect of vacuum fluctuation.

We discuss an atomic waveguide that guides atoms in a similar way a quadrupole mass spectrometer guides charged particles. A two dimensional guiding potential barrier is produced by repulsive optical dipole forces caused by evanescent waves from optical fibers. A realization of this new atom optical element is proposed.

We have made a quantitative study of quantum electrodynamic corrections to the atomic energy levels between parallel conducting mirrors. Within the framework of simple two-level atoms, we evaluate the level shifts numerically and discuss the van der Waals, Casimir, and cavity-resonant radiative shifts as their asymptotic forms. In particular, we find that the level shifts of an excited state are substantially different not only from those of a classical dipole radiator but also from those of an