Zobrazeno 1 - 10
of 85
pro vyhledávání: '"Humphrey, J. A."'
Autor:
Humphrey J. Maris, Sébastien Balibar
Publikováno v:
Journal of Low Temperature Physics. 147:539-547
The specific heat of solid helium in the temperature range below about 1.2 K has been found to contain a term varying as T 7, in addition to the usual T 3 contribution always found in a crystalline dielectric solid. It has been proposed by Anderson,
Publikováno v:
physica status solidi (b). 242:1379-1382
We report measurements of the sound velocity as a function of temperature in water using the picosecond acoustic interferometry technique. We show that this method can be used to make velocity measurements on very small sample volumes. (© 2005 WILEY
Autor:
Wisit Singhsomroje, Humphrey J. Maris
Publikováno v:
physica status solidi (b). 241:3463-3468
We describe experiments to study the propagation of phonon solitons in crystalline solids. A picosecond light pulse is used to generate a short strain pulse. As this pulse propagates, its shape changes as a result of phonon dispersion and elastic non
Autor:
H. Eguchi, B. Sethumadhavan, George M. Seidel, R. E. Lanou, A. N. Mocharnuk‐Macchia, Y.H Kim, Christian Enss, W. Yao, Y. H. Huang, Humphrey J. Maris
Publikováno v:
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 520:208-211
The response of a magnetic calorimeter with a sapphire crystal serving as an X-ray absorber has been studied as a function of temperature. Several different Au films were used to connect thermally the magnetic sensor to the absorber. The amplitude an
Publikováno v:
PHYSICAL REVIEW B. 60(4):2627-2630
With the use of a face-centered cubic model of lattice dynamics we calculate the group velocity of acoustic phonons in the growth direction of periodic superlattices. Comparing with the case of bulk solids, this component of the phonon group velocity
Publikováno v:
Physical Review B. 59:10105-10110
We present an analysis of recent thermal-conductivity measurements on crystalline silicon in which the concentration of the {sup 28}Si isotope has been increased above the natural abundance. We calculate from the phonon Boltzmann equation the change
Autor:
Humphrey J. Maris, Hsin-Yi Hao
Publikováno v:
Physica B: Condensed Matter. :670-673
Although the dispersion relation for phonons propagating in crystalline lattice has been studied for many years, the effect of lattice dispersion on the shape of a propagating pulse has not been studied experimentally. We report on an observation of
Autor:
Humphrey J. Maris, Guray Tas
Publikováno v:
Physical Review B. 55:1852-1857
We have studied the reflection of longitudinal-acoustic phonons with frequencies between 100 and 300 GHz from solid-liquid interfaces using a picosecond ultrasonic technique. Acoustic phonons were generated by absorption of a picosecond light pulse i
Autor:
Humphrey J. Maris, C.J. Morath
Publikováno v:
Physical Review B. 54:203-213
We have used a picosecond optical technique to measure the attenuation {alpha} of longitudinal-acoustic phonons in several disordered solids. We find a universal {alpha}{approximately}{nu}{sup 2} behavior for frequencies {nu} up to 320 GHz and for te
Autor:
S. Tamura, Humphrey J. Maris
Publikováno v:
Physical Review B. 51:2857-2863
We present calculations of the temperature dependence of the lifetime of phonons due to anharmonic interactions. The contributions to the lifetime arising from phonon decay and phonon-phonon collisions are considered separately and, in addition, the