41,381 research outputs found
Valley Polarization in Si(100) at Zero Magnetic Field
The valley splitting, which lifts the degeneracy of the lowest two valley
states in a SiO/(100)Si/SiO quantum well is examined through transport
measurements. We demonstrate that the valley splitting can be observed directly
as a step in the conductance defining a boundary between valley-unpolarized and
polarized regions. This persists to well above liquid helium temperature and
shows no dependence on magnetic field, indicating that single-particle valley
splitting and valley-polarization exist in (100) silicon even at zero magnetic
field.Comment: Accpeted for publication in Phys. Rev. Let
Nonlinearly Realized Extended Supergravity
We provide nonlinear realization of supergravity with an arbitrary number of
supersymmetries by means of coset construction. The number of gravitino degrees
of freedom counts the number of supersymmetries, which will be possibly probed
in future experiments. We also consider goldstino embedding in the construction
to discuss the relation to nonlinear realization with rigid supersymmetries.Comment: 19 page
Current-feedback-stabilized laser system for quantum simulation experiments using Yb clock transition at 578 nm
We developed a laser system for the spectroscopy of the clock transition in
ytterbium (Yb) atoms at 578 nm based on an interference-filter stabilized
external-cavity diode laser (IFDL) emitting at 1156 nm. Owing to the improved
frequency-to-current response of the laser-diode chip and the less sensitivity
of the IFDL to mechanical perturbations, we succeeded in stabilizing the
frequency to a high-finesse ultra-low-expansion glass cavity with a simple
current feedback system. Using this laser system, we performed high-resolution
clock spectroscopy of Yb and found that the linewidth of the stabilized laser
was less than 320 Hz.Comment: 5 pages, 7 figure
An improved method for determining the DC magnetization curve using a ring specimen
When the DC magnetization curve (B-H) of nonoriented material is measured in a ring specimen, there is an intrinsic error due to the assumption that the mean magnetic path length is equal to the mean geometric path length. A novel method for determining the B-H curve accurately is proposed. The validity of the method is verified by experiments</p
The applicability of the catalytic wet-oxidation to CELSS
The wet oxidation catalysis of Au, Pd, Pt, Rh or Ru on a ceramic honeycomb carrier was traced in detail by 16 to 20 repetitive batch tests each. As a result, Pt or Pd on a honeycomb carrier was shown to catalyze complete nitrogen gasification as N2. Though the catalysts which realize both complete nitrogen gasification and complete oxidation could not be found, the Ru+Rh catalyst was found to be most promising. Ru honeycomb catalyzed both nitrification and nitrogen gasification
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