Ratchet is a device that produces direct current of particles when driven by an unbiased force. We demonstrate a simple scattering quantum ratchet based on an asymmetrical quantum tunneling effect in two-dimensional electron gas with Rashba spin-orbit interaction (R2DEG). We consider the tunneling of electrons across a square potential barrier sandwiched by interface scattering potentials of un...

High-resolution spectra of the intramolecular bending modes of deuterated water dimer, (D2O)2, have been measured using a quantum cascade laser based cavity ringdown spectrometer. Two perpendicular bands have been observed and are assigned as the K(a) = 1 ← 0 and K(a) = 2 ← 1 bands of the bending mode of the hydrogen bond donor. The tunneling splittings in the complex are well-resolved, and it ...

This work establishes a firm relationship between classical nonlinear resonances and the phenomenon of dynamical tunneling. It is shown that the classical phase space with its hierarchy of resonance islands completely characterizes dynamical tunneling and explicit forms of the dynamical barriers can be obtained only by identifying the key resonances. Relationship between the phase space viewpoi...

Cobalt was deposited by physical vapor deposition onto thin well-ordered niobia films in order to model niobia supported Co catalysts. Adsorption of CO on the Co/niobia surfaces was studied by temperature programmed desorption and infrared reflection absorption spectroscopy. Structural characterization was performed by photoelectron spectroscopy and scanning tunneling microscopy. Cobalt was fou...

Using the Bogoliubov-de Gennes equation, we study the quasi-particle spectra around a single vortex in a d-wave superconductor, where a magnetic field is parallel to the c-axis. In the temperature region where the Ginzburg-Landau theory is valid, we find that the local density of states preserves a circular symmetry when the symmetry of the superconducting order parameter is pure d-wave. It, ho...

Quantum Zeno Effect (QZE) is the suppression of the inter-subspace transition by a relatively fast intra-subspace decoherence. Earlier, we had proposed a QZE-based mechanism for the temperature-dependent normal-state c-axis resistivity of the layered high-Tc cuprate superconductors in which the singleparticle inter-layer tunneling is blocked by the strong intra-layer decoherence (entanglement)....

Tunneling nanotubes are important membrane channels for cell-to-cell communication. In this study, we investigated the effect of the microenvironment on nanotubular structures by preparing a three-dimensional silk fibroin micropillar structure. In previous reports, tunneling nanotubes were described as stretched membrane channels between interconnected cells at their nearest distance. They hove...

Electrode/nanopore structures hold promise towards the fabrication, functionalization and control of nanopore sensor performance. This includes "simple" one-electrode structures, where an additional membrane electrode is used to control the electrostatic properties of the nanopore, but also more sophisticated two-electrode junction devices, integrating tunneling detection with nanopore-based si...

We study effect of noise on the tunneling process of the magnetization in a sweeping field from the viewpoint of the nonadiabatic transition. The tunneling probability depends on the properties of the noise, e.g. the direction, the amplitude, and the relaxation time of the autocorrelation function. We investigate the tunneling process in the presence of noise by solving the time-dependent Schrö...

We studied the atomic structure of ultrathin silica films on Pt(111) in comparison with the previously studied films on Mo(112) and Ru(0001). The results obtained by scanning tunneling microscopy, photoelectron spectroscopy and infrared reflection absorption spectroscopy suggest that the metal-oxygen bond strength plays the decisive role in the atomic structure of the silica overlayers on metal...