We have measured the transport properties of high-quality quantum wires fabricated in GaAs-AlGaAs by using cleaved edge overgrowth. The low temperature conductance is quantized as the electron density in the wire is varied. While the values of the conductance plateaus are reproducible, they deviate from multiples of the universal value of 2e2yh by as much as 25%. As the temperature or dc bias i...

We introduce four new molecules—YbRb, YbCs, YbSr+, and YbBa+—that may prove fruitful in experimental searches for the electric-dipole moment EDM of the electron. These molecules can, in principle, be prepared at extremely low temperatures by photoassociating ultracold atoms and therefore may present an advantage over molecular-beam experiments. Here we discuss properties of these molecules and ...

The shape of the electron energy distribution has long been a central question in the field of high-frequency radio-induced optical emission experiments. This report presents estimates of the electron energy distribution function, , from 0 to 60 based on optical multiwavelength (6300, 5577, 8446, 4278 ̊ ) data and 930incoherent scatter radar measurements of ion temperature, electron temperature...

We have measured the frequency dependent IF impedance and mixer conversion gain of a small area NbN hot-electron bolometer (HEB). The device used is a twin slot antenna coupled NbN HEB mixer with a bridge area of 1 μm x 0.15 μm, and a critical temperature of 8.3 K. In the experiment the local oscillator (LO) frequency was 1.300 THz, and the intermediate frequency (IF) 0.05-10 GHz. We find that ...

We investigate hysteresis in the transport properties of superconductor-normal-metal-superconductor (S-N-S) junctions at low temperatures by measuring directly the electron temperature in the normal metal. Our results demonstrate unambiguously that the hysteresis results from an increase of the normal-metal electron temperature once the junction switches to the resistive state. In our geometry,...

This paper reports progress on gyrokinetic particle simulation of turbulence in fusion plasmas including: (1) Electron transport driven by short wavelength trapped electron mode turbulence; (2) Convergence studies and physics progress in long time simulation of electron temperature gradient turbulence; (3) Electromagnetic simulation of global magnetohydrodynamic modes and finite-β stabilization...

Improved and reproducible heterodyne mixing (noise temperatures of 950 K at 2.5 THz) has been realized with NbN based hot-electron superconducting devices with low contact resistances. A distributed temperature numerical model of the NbN bridge, based on a local electron and a phonon temperature, has been used to understand the physical conditions during the mixing process. We find that the mix...

Abal~ct We have studied electron heating in a 2DEG in GaAs/AIGaAs heterojunctions below 0.5 IC The electron temperature was raised above the lattice temperature using Joule heat/n& Weak localiT~tion and the temperature-dependent sample resistance were used as thermometers for the electrons. The electron-phonon energy relaxation rate was found to be proportional to T s. We find that the relaxati...

FePt nanoparticles with thermally stable room-temperature ferromagnetism are investigated. The monodisperse nanoparticles are prepared by chemical synthesis and a salt-matrix annealing technique. Structural and magnetic characterizations confirm the phase transition from the disordered face-centered cubic structure. In this paper, 3 nm FePt nanoparticles are first synthesized by superhydride re...

Sawtooth oscittations in the themonuctea& neutton ptoduction Aate have been ob.erved in AtcatoA. They axe coAtelated with oscdJations in zoit x-ay emizzion 6'Lom the p&a.ma and indicate tavge (>15%) o6ciftation4 o6 centWaL ion tempexatue. Soft x-ray emission from the Alcator plasma has been observed using a multi-diode imaging apparatus built by Petrasso et al [1]. The x-ray flux exhibits the c...