Showing papers by "Mildred S. Dresselhaus published in 1995"
TL;DR: In this paper, the symmetry properties of carbon nanotubes for both symmorphic and non-symmorphic tubules which have screw-axis symmetry are discussed. And the implications of symmetry on the vibrational and electronic structure of 1D carbon nanite systems are considered.
1,061 citations
TL;DR: In this article, the authors measured the nonlinear surface impedanceZs in a number of YBa2Cu3O7−x thin films as a function of frequency from 1 to 18 GHz, surface magnetic fieldHrf to 1500 Oe, and temperature from 4 K to Tc. The results at lowHrf were shown to agree quantitatively with a modified coupled-grain model and at highHrf with hysteresis-loss calculations using the Bean critical-state model applied to a thin strip.
Abstract: High-Tc thin films continue to be of interest for passive device applications at microwave frequencies, but nonlinear effects may limit the performance. To understand these effects we have measured the nonlinear surface impedanceZs in a number of YBa2Cu3O7−x thin films as a function of frequency from 1 to 18 GHz, rf surface magnetic fieldHrf to 1500 Oe, and temperature from 4 K toTc. The results at lowHrf are shown to agree quantitatively with a modified coupled-grain model and at highHrf with hysteresis-loss calculations using the Bean critical-state model applied to a thin strip. The loss mechanisms are extrinsic properties resulting from defects in the films. We also report preliminary measurements of the nonlinear impedance of Josephson junctions, and the results are related to the models of nonlinearZS. The implications of nonlinearZS for devices are discussed using the example of a five-pole bandpass filter.
32 citations
TL;DR: In this paper, the magnetic coupling of MBE-grown (111) EuTe PbTe superlattices has been investigated in the presence of antiferromagnetically coupled spin sheets.
12 citations
24 Apr 1995
TL;DR: In this article, the femtosecond time-resolved pump-probe experiments have detected large amplitude oscillations due to coherent phonon generation in the reflection (R) from various materials.
Abstract: Recent femtosecond time-resolved pump-probe experiments have detected large amplitude oscillations due to coherent phonon generation in the reflection (R) from various materials). These oscillations show only vibrational modes with A1 symmetry, even though other Raman-active modes of comparable Raman cross section exist. Experimental results showing the properties of this phenomena and a model that explains many of the experimental phenomena are presented.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
1 citations