The Experts below are selected from a list of 210 Experts worldwide ranked by ideXlab platform
R A Duine - One of the best experts on this subject based on the ideXlab platform.
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magnons versus electrons in thermal spin transport through metallic interfaces
Journal of Physics D, 2018Co-Authors: Maarten Beens, Joseph P Heremans, Yaroslav Tserkovnyak, R A DuineAbstract:We develop a theory for spin transport in magnetic metals that treats the Contribution of magnons and electrons on equal footing. As an application, we consider thermally-driven spin injection across an interface between a magnetic metal and a normal metal, i.e. the spin-dependent Seebeck effect. We show that the ratio between magnonic and Electronic Contribution scales as , with the Fermi temperature T F and the Curie temperature T C . Since, typically, , the magnonic Contribution may dominate the thermal spin injection, even though the interface is more transparent for Electronic spin current.
B Buchner - One of the best experts on this subject based on the ideXlab platform.
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specific heat and angle resolved photoemission spectroscopy study of the superconducting gaps in lifeas
Physical Review B, 2011Co-Authors: U Stockert, M Abdelhafiez, D V Evtushinsky, V B Zabolotnyy, A U B Wolter, Sabine Wurmehl, I V Morozov, R Klingeler, S V Borisenko, B BuchnerAbstract:We present specific heat, c_P, and ARPES data on single crystals of the stoichiometric superconductor LiFeAs. A pronounced anomaly is found in c_P at the superconducting transition. The Electronic Contribution can be described by two s-type energy gaps with magnitudes of approximately Delta1 = 1.2 meV and Delta2 = 2.6 meV and a normal-state gamma coefficient of 10 mJ/mol K^2. All these values are in remarkable agreement with ARPES results.
K. P. Ghatak - One of the best experts on this subject based on the ideXlab platform.
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A simple theoretical analysis of the Electronic Contribution to the elastic constants in strained layer superlattices of non-parabolic semiconductors under magnetic quantization
2020Co-Authors: K. P. Ghatak, J. Mukhopadhyay, J. P. BanerjeeAbstract:We study the Electronic Contribution to the elastic constants in strained layer superlattices of non-parabolic semiconductors with graded structures under strong magnetic quantization and compare the same with the bulk specimens of the constituent materials, by formulating the appropriate magneto-dispersion laws. It is found, taking InSb /GaSb superlattice as an example, that the said Contribution oscillates with the inverse quantizing magnetic field due to the Shubnikov - de Hass effect. An experimental method is suggested for determining the Electronic Contribution to the elastic constants in materials having arbitrary dispersion laws.
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On The Electronic Contribution to Elastic Constants of Ultrathin Films of P-Type Si
MRS Proceedings, 2011Co-Authors: K. P. Ghatak, Badal DeAbstract:AbstractIn this paper we have formulated the Electronic Contribution to the elastic constants in ultrathin films of p-Si by considering the influences of heavy, light and split-off holes respectively. We have suggested an experimental method of determining the same in degenerate materials having arbitrary dispersion laws. The elastic constants increase with increasing hole concentration in an oscillatory way and decrease with increasing film thickness. The theoretical formulation is in agreement with the suggested experimental method of determining second and third order elastic constants.
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The Electronic Contribution to The Elastic Constants of Strained III-V Materials Under High Magnetic Fields
MRS Proceedings, 2011Co-Authors: K. P. Ghatak, G. MazumderAbstract:ABSTRACTIn this paper an attempt is made to study the Electronic Contribution to the elastic constants of strained III-V materials under high magnetic fields on the basis of k.p theory. It is found taking strained Hgi - x CdxTe and Ini - xGaxAsyPi-y lattice matched InP as examples that they increase with increasing doping and oscillate with inverse magnetic field respectively. The strain enhances the numerical values of the elastic constants. The theoretical formulation is in quantitative agreement with the suggested experimental method of determining the above Contributions for degenerate materials having arbitrary dispersion laws. In addition, the well-known results for strain free wide gap materials in the absence of magnetic field have been obtained from our generalized analysis under certain limiting conditions.
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The Electronic Contribution to the elastic constants in strained layer quantum well superlattices of non-parabolic semiconductors with graded interfaces under magnetic quantization: Simplified theory and suggestion for experimental determination
Physica B-condensed Matter, 2005Co-Authors: S. Chowdhary, L. J. Singh, K. P. GhatakAbstract:In this paper, we study the Electronic Contribution to the elastic constants in strained layer quantum well superlattices of non-parabolic semiconductors with graded structures under strong magnetic quantization and compare the same with that of the constituent materials, by formulating the appropriate dispersion laws. It is found, taking InSb/GaSb quantum well strained superlattices of non-parabolic semiconductors as an example, that the carrier Contribution to the second- and third-order elastic constants oscillates both with the Electronic concentration and the inverse quantizing magnetic field in different manners together with the fact that the nature of oscillations is totally band structure dependent. We have also suggested an experimental method for determining the Electronic Contribution to the elastic constants in low-dimensional materials having arbitrary dispersion laws. In addition, the well-known results for bulk specimens of wide-gap stress-free materials have been obtained as special cases from our generalized formulation under certain limiting conditions.
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ON THE Electronic Contribution TO THE ELASTIC CONSTANTS IN STRAINED QUANTUM WIRE SUPERLATTICES OF NON-PARABOLIC SEMICONDUCTORS WITH GRADED STRUCTURES : THEORY AND SUGGESTION FOR EXPERIMENTAL DETERMINATION
Il Nuovo Cimento D, 1998Co-Authors: K. P. Ghatak, S. Dutta, D. K. BasuAbstract:We study the Electronic Contribution to the second- and third-order elastic constants in strained quantum wire superlattices of non-parabolic semiconductors with graded structures and compare the same with the constituent materials, by formulating the appropriate dispersion laws. It is found, taking InSb/GaSb quantum wire superlattice as an example, that the said Contributions increase with decreasing thickness and with increasing electron concentration in oscillatory manners together with the fact that the influence of the finite interface width enhances their numerical values. An experimental method is suggested for determining the Electronic Contribution to the elastic constants in materials having arbitrary dispersion laws. In addition, the well-known results for constituent semiconductors in the absence of stress have also been obtained as special cases of our generalized formulations.
U Stockert - One of the best experts on this subject based on the ideXlab platform.
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specific heat and angle resolved photoemission spectroscopy study of the superconducting gaps in lifeas
Physical Review B, 2011Co-Authors: U Stockert, M Abdelhafiez, D V Evtushinsky, V B Zabolotnyy, A U B Wolter, Sabine Wurmehl, I V Morozov, R Klingeler, S V Borisenko, B BuchnerAbstract:We present specific heat, c_P, and ARPES data on single crystals of the stoichiometric superconductor LiFeAs. A pronounced anomaly is found in c_P at the superconducting transition. The Electronic Contribution can be described by two s-type energy gaps with magnitudes of approximately Delta1 = 1.2 meV and Delta2 = 2.6 meV and a normal-state gamma coefficient of 10 mJ/mol K^2. All these values are in remarkable agreement with ARPES results.
Soongil Yoon - One of the best experts on this subject based on the ideXlab platform.
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effect of Electronic Contribution on temperature dependent thermal transport of antimony telluride thin film
Journal of Alloys and Compounds, 2015Co-Authors: Nowon Park, Jieun Hong, Soongil YoonAbstract:Abstract We study the theoretical and experimental characteristics of thermal transport of 100 nm and 500 nm-thick antimony telluride (Sb 2 Te 3 ) thin films prepared by radio frequency magnetron sputtering. The thermal conductivity was measured at temperatures ranging from 20 to 300 K, using four-point-probe 3- ω method. Out-of-plane thermal conductivity of the Sb 2 Te 3 thin film was much lesser in comparison to the bulk material in the entire temperature range, confirming that the phonon- and electron-boundary scattering are enhanced in thin films. Moreover, we found that the Contribution of the Electronic thermal conductivity ( κ e ) in total thermal conductivity ( κ ) linearly increased up to ∼77% at 300 K with increasing temperature. We theoretically analyze and explain the high Contribution of Electronic component of thermal conductivity towards the total thermal conductivity of the film by a modified Callaway model. Further, we find the theoretical model predictions to correspond well with the experimental results.