ar X iv : c on d - m at / 9 90 10 69 v 1 8 J an 1 99 9 Theory of sound attenuation in glasses : The role of thermal vibrations

ar X iv : c on d - m at / 9 60 31 90 v 1 2 9 M ar 1 99 6 The Four - Dimensional XY Spin Glass

ar X iv : c on d - m at / 9 90 90 44 v 1 3 S ep 1 99 9 Systematic low temperature expansion in Ginzburg - Landau model

Consistent perturbation theory for thermodynamical quantities in strongly type II superconductors in magnetic field at low temperatures is developed. It is complementary to the existing expansion valid at high temperatures. Magnetization and specific heat are calculated to two loop order and compare well with existing Monte Carlo simulations, other theories and experiments. Typeset using REVTEX 1

Theory of Sound Attenuation in Glasses: The Role of Thermal Vibrations

Sound attenuation and internal friction coefficients are calculated for a realistic model of amorphous silicon. It is found that, contrary to previous views, thermal vibrations can induce sound attenuation at ultrasonic and hypersonic frequencies that is of the same order or even larger than in crystals. The reason is the internal strain induced anomalously large Grüneisen parameters of the low...

ar X iv : c on d - m at / 9 30 70 65 v 1 2 9 Ju l 1 99 3 Chaos in short - range spin glasses

The nature of static chaos in spin glasses is studied. For the problem of chaos with magnetic field, scaling relations in the case of the SK model and short-range models are presented. Our results also suggest that if there is de Almeida-Thouless line then it is similar to that of mean-field theory for d = 4 and close to the h = 0 axis for d = 3. We estimate the lower critical dimension to be i...

ar X iv : c on d - m at / 9 90 84 00 v 1 2 7 A ug 1 99 9 Thermodynamics of hexagonal - close - packed iron under Earth ’ s core conditions

The free energy and other thermodynamic properties of hexagonal-close-packed iron are calculated by direct ab initio methods over a wide range of pressures and temperatures relevant to the Earth’s core. The ab initio calculations are based on density-functional theory in the generalisedgradient approximation, and are performed using the projector augmented wave (PAW) approach. Thermal excitatio...