The Experts below are selected from a list of 279321 Experts worldwide ranked by ideXlab platform
Youbin Yu - One of the best experts on this subject based on the ideXlab platform.
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electron phonon Interaction effect on optical absorption in cylindrical quantum wires
Solid State Communications, 2006Co-Authors: Youbin YuAbstract:Abstract Electron–phonon Interaction effects on linear and nonlinear optical absorption in cylindrical quantum wires are investigated. The linear and nonlinear optical absorption coefficients are obtained by using compact-density-matrix approach and iterative method, and the numerical results are presented for GaAs/AlAs cylindrical quantum-well wires. The results show that electron–phonon Interaction not only influences the relaxation rate but also distinctly influences the wave functions and energies of the electron. The correction of electron–phonon Interaction effect on the wave functions of the electron dominates the values of absorption coefficients. Moreover, the correction of electron–phonon Interaction effect on the energies of the electron makes the absorption peaks blue shift and become wider.
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polaron influence on the third order nonlinear optical susceptibility in cylindrical quantum wires
Physica E-low-dimensional Systems & Nanostructures, 2005Co-Authors: Youbin YuAbstract:Abstract Electron–phonon Interaction effect on third-harmonic generation (THG) in cylindrical quantum wires are investigated. The THG coefficient is obtained by using the compact-density-matrix approach and iterative method, and the numerical results are presented for GaAs cylindrical quantum wires. The results show that the THG coefficient is greatly enhanced and the peak shift to the aspect of high energy because of considering the influence of electron–phonon Interaction.
Jiansheng Wang - One of the best experts on this subject based on the ideXlab platform.
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thermal transport across metal insulator interface via electron phonon Interaction
Journal of Physics: Condensed Matter, 2013Co-Authors: Lifa Zhang, Jiansheng WangAbstract:The thermal transport across a metal–insulator interface can be characterized by electron–phonon Interaction through which an electron lead is coupled to a phonon lead if phonon–phonon coupling at the interface is very weak. We investigate the thermal conductance and rectification between the electron part and the phonon part using the nonequilibrium Green's function method. It is found that the thermal conductance has a nonmonotonic behavior as a function of average temperature or the coupling strength between the phonon leads in the metal part and the insulator part. The metal–insulator interface shows a clear thermal rectification effect, which can be reversed by a change in average temperature or the electron–phonon coupling.
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thermal transport across metal insulator interface via electron phonon Interaction
arXiv: Materials Science, 2013Co-Authors: Lifa Zhang, Jiansheng WangAbstract:The thermal transport across metal-insulator interface can be characterized by Electron-Phonon Interaction through which an electron lead is coupled to a phonon lead if phonon-phonon coupling at the interface is very weak. We investigate the thermal conductance and rectification flowing between the electron part and the phonon part using nonequilibrium Green's function method. It is found that the thermal conductance has a nonmonotonic behavior as a function of average temperature or the coupling strength between the phonon leads in the metal part and the insulator one. The metal-insulator interface shows evident thermal rectification effect, which can reverse with changing of average temperature or the Electron-Phonon coupling.
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joule heating and thermoelectric properties in short single walled carbon nanotubes electron phonon Interaction effect
Journal of Applied Physics, 2011Co-Authors: Jinwu Jiang, Jiansheng WangAbstract:The Electron-Phonon Interaction (EPI) effect in single-walled carbon nanotube is investigated by the nonequilibrium Green’s function approach within the Born approximation. Special attention is paid to the EPI induced Joule heating phenomenon and the thermoelectric properties in both metallic armchair (10, 10) tube and semiconductor zigzag (10, 0) tube. For Joule heat in the metallic (10, 10) tube, the theoretical results for the breakdown bias voltage is quite comparable with the experimental value. It is found that the Joule heat can be greatly enhanced by increasing the chemical potential, while the role of the temperature is not so important for Joule heat. In the zigzag (10, 0) tube, the Joule heat is smaller than the armchair tube, resulting from nonzero bandgap in the electron band structure. For the electronic conductance Ge and electron thermal conductance σel, the EPI has important effect at higher temperature or higher chemical potential. Compared with ballistic transport, there is an opposite ...
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joule heating and thermoelectric properties in short single walled carbon nanotubes electron phonon Interaction effect
arXiv: Materials Science, 2011Co-Authors: Jinwu Jiang, Jiansheng WangAbstract:The Electron-Phonon Interaction (EPI) effect in single-walled carbon nanotube is investigated by the nonequilibrium Green's function approach within the Born approximation. Special attention is paid to the EPI induced Joule heating phenomenon and the thermoelectric properties in both metallic armchair (10, 10) tube and semiconductor zigzag (10, 0) tube. For Joule heat in the metallic (10, 10) tube, the theoretical results for the breakdown bias voltage is quite comparable with the experimental value. It is found that the Joule heat can be greatly enhanced by increasing the chemical potential, while the role of the temperature is not so important for Joule heat. In zigzag (10, 0) tube, the Joule heat is smaller than the armchair tube, resulting from nonzero band gap in the electron band structure. For the electronic conductance $G_{e}$ and electron thermal conductance $\sigma_{el}$, the EPI has important effect at higher temperature or higher chemical potential. Compared with ballistic transport, there is an opposite tendency for $G_{e}$ to decrease with increasing temperature after EPI is considered. This is due to the dominant effect of the electron phonon scattering mechanism in the electron transport in this situation. There is an interesting `electron-drag' phenomenon for the phonon thermal conductance in case of low temperature and high chemical potential, where phonons are dragged by electrons from low temperature region into high temperature region through EPI effect.
Naoto Nagaosa - One of the best experts on this subject based on the ideXlab platform.
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manifestations of the electron phonon Interaction range in angle resolved photoemission spectra
Physical Review B, 2020Co-Authors: J Krsnik, Naoto Nagaosa, V N Strocov, O S Barisic, Zoran Rukelj, S M Yakubenya, A S MishchenkoAbstract:Numerous angle-resolved photoemission spectroscopy (ARPES) studies of a wide class of low-density metallic systems, ranging from doped transition metal oxides to quasi-two-dimensional interfaces between insulators, exhibit phonon sidebands below the quasiparticle peak as a unique hallmark of polaronic correlations. Here, we single out properties of ARPES spectra that can provide a robust estimate of the effective range (screening length) of the Electron-Phonon Interaction, regardless of the limited experimental resolution, dimensionality, and particular features of the electronic structure, facilitating a general methodology for an analysis of a whole class of materials.
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Angle-Resolved Photoemission Spectroscopy on Electronic Structure and Electron-Phonon Coupling in Cuprate Superconductors
arXiv: Strongly Correlated Electrons, 2006Co-Authors: Xingjiang Zhou, T P Devereaux, Naoto Nagaosa, Tanja Cuk, Zhixun ShenAbstract:This treatise reviews latest results obtained from angle-resolved photoemission spectroscopy (ARPES) on cuprate superconductors, with a special focus on the Electron-Phonon Interaction. What has emerged is rich information about the anomalous Electron-Phonon Interaction well beyond the traditional views of the subject. It exhibits strong doping, momentum and phonon symmetry dependence, and shows complex interplay with the strong electron-electron Interaction in these materials.
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anisotropic electron phonon Interaction in the cuprates
Physical Review Letters, 2004Co-Authors: T P Devereaux, Zhixun Shen, Naoto NagaosaAbstract:: We explore manifestations of Electron-Phonon coupling on the electron spectral function for two phonon modes in the cuprates exhibiting strong renormalizations with temperature and doping. Applying simple symmetry considerations and kinematic constraints, we find that the out-of-plane, out-of-phase O buckling mode (B(1g)) involves small momentum transfers and couples strongly to electronic states near the antinode while the in-plane Cu-O breathing modes involve large momentum transfers and couples strongly to nodal electronic states. Band renormalization effects are found to be strongest in the superconducting state near the antinode, in full agreement with angle-resolved photoemission spectroscopy data.
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interplay of electron phonon Interaction and electron correlation in high temperature superconductivity
Physical Review B, 2004Co-Authors: Sumio Ishihara, Naoto NagaosaAbstract:We study the Electron-Phonon Interaction in the strongly correlated superconducting cuprates. Two types of the Electron-Phonon Interactions are introduced in the $t\ensuremath{-}J$ model; the diagonal and off-diagonal Interactions which modify the formation energy of the Zhang-Rice singlet and its transfer integral, respectively. The characteristic phonon-momentum $(\stackrel{\ensuremath{\rightarrow}}{q})$ and electron-momentum $(\stackrel{\ensuremath{\rightarrow}}{k})$ dependence that resulted from the off-diagonal coupling can explain a variety of experiments. The vertex correction for the Electron-Phonon Interaction is formulated in the SU(2) slave-boson theory by taking into account the collective modes in the superconducting ground states. It is shown that the vertex correction enhances the attractive potential for the d-wave paring mediated by phonon with $\stackrel{\ensuremath{\rightarrow}}{q}=[\ensuremath{\pi}(1\ensuremath{-}\ensuremath{\delta}),0]$ around $\ensuremath{\delta}\ensuremath{\cong}0.3,$ which corresponds to the half-breathing mode of the oxygen motion.
Gang Chen - One of the best experts on this subject based on the ideXlab platform.
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direct observation of large electron phonon Interaction effect on phonon heat transport
Nature Communications, 2020Co-Authors: Jiawei Zhou, Hyun D Shin, Ke Chen, Bai Song, R A Duncan, A A Maznev, Keith A Nelson, Gang ChenAbstract:As a foundational concept in many-body physics, Electron-Phonon Interaction is essential to understanding and manipulating charge and energy flow in various electronic, photonic, and energy conversion devices. While much progress has been made in uncovering how phonons affect electron dynamics, it remains a challenge to directly observe the impact of electrons on phonon transport, especially at environmental temperatures. Here, we probe the effect of charge carriers on phonon heat transport at room temperature, using a modified transient thermal grating technique. By optically exciting electron-hole pairs in a crystalline silicon membrane, we single out the effect of the phonon-carrier Interaction. The enhanced phonon scattering by photoexcited free carriers results in a substantial reduction in thermal conductivity on a nanosecond timescale. Our study provides direct experimental evidence of the elusive role of Electron-Phonon Interaction in phonon heat transport, which is important for understanding heat conduction in doped semiconductors. We also highlight the possibility of using light to dynamically control thermal transport via Electron-Phonon coupling.
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effect of electron phonon Interaction on lattice thermal conductivity of sige alloys
Applied Physics Letters, 2019Co-Authors: Jiawei Zhou, Tehuan Liu, Gang ChenAbstract:While it is well-known that Electron-Phonon scattering often determines the electron mobility, its impact on lattice thermal conductivity is less clear. Dominant phonon scattering mechanisms that determine the lattice thermal conductivity have been attributed to phonon-phonon and phonon-defect Interactions. However, recent studies in silicon have shown that strong Electron-Phonon Interaction can also lead to significant phonon scatterings at high carrier concentrations. Here, we use first-principles simulations to study thermal transport in SiGe alloys and show that the effect of Electron-Phonon Interaction on thermal transport is even more significant than that in Si because mass disorder scattering leaves long mean free path phonons behind, which are more strongly scattered by electrons. At the carrier concentration of 1 × 1020 cm−3, the room temperature lattice thermal conductivity of the Si0.9Ge0.1 alloy including Electron-Phonon Interaction is only 40% of the value without this Interaction. The results show that thermal transport in alloys at a high doping level can be significantly impacted by the free carriers, providing important insights into heat conduction mechanisms in thermoelectric materials which are mostly based on heavily doped alloys.
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ab initio study of electron phonon Interaction in phosphorene
Physical Review B, 2015Co-Authors: Bolin Liao, Jiawei Zhou, Bo Qiu, Mildred S Dresselhaus, Gang ChenAbstract:The monolayer of black phosphorous, or phosphorene, has recently emerged as a new 2D semiconductor with intriguing highly anisotropic transport properties. Existing calculations of its intrinsic phonon-limited electronic transport properties so far rely on the deformation potential approximation, which is in general not directly applicable to anisotropic materials since the deformation along one specific direction can scatter electrons traveling in all directions. We perform a first-principles calculation of the Electron-Phonon Interaction in phosphorene based on density functional perturbation theory and Wannier interpolation. Our calculation reveals that 1) the high anisotropy provides extra phase space for Electron-Phonon scattering, and 2) optical phonons have appreciable contributions. Both effects cannot be captured by the deformation potential calculations.
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ab initio study of electron phonon Interaction in phosphorene
Physical Review B, 2015Co-Authors: Bolin Liao, Jiawei Zhou, Bo Qiu, Mildred S Dresselhaus, Gang ChenAbstract:The monolayer of black phosphorus, or ``phosphorene,'' has recently emerged as a two-dimensional semiconductor with intriguing highly anisotropic transport properties. Existing calculations of its intrinsic phonon-limited electronic transport properties so far rely on the deformation potential approximation, which is in general not directly applicable to anisotropic materials since the deformation along one specific direction can scatter electrons traveling in all directions. We perform a first-principles calculation of the Electron-Phonon Interaction in phosphorene based on density functional perturbation theory and Wannier interpolation. Our calculation reveals that (1) the high anisotropy provides extra phase space for Electron-Phonon scattering, and (2) optical phonons have appreciable contributions. Both effects cannot be captured by the deformation potential calculations. Our simulation predicts carrier mobilities $\ensuremath{\sim}170\phantom{\rule{0.16em}{0ex}}\mathrm{c}{\mathrm{m}}^{2}/\mathrm{V}\phantom{\rule{0.16em}{0ex}}\mathrm{s}$ for both electrons and holes at $300\phantom{\rule{0.16em}{0ex}}\mathrm{K}$, and a thermoelectric figure of merit $zT$ of up to 0.14 in $p$-type impurity-free phosphorene at $500\phantom{\rule{0.16em}{0ex}}\mathrm{K}$.
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ab initio study of electron phonon Interaction in phosphorene
Physical Review Letters, 2015Co-Authors: Bolin Liao, Jiawei Zhou, Bo Qiu, Mildred S Dresselhaus, Gang ChenAbstract:The monolayer of black phosphorus, or “phosphorene,” has recently emerged as a two-dimensional semiconductor with intriguing highly anisotropic transport properties. Existing calculations of its intrinsic phonon-limited electronic transport properties so far rely on the deformation potential approximation, which is in general not directly applicable to anisotropic materials since the deformation along one specific direction can scatter electrons traveling in all directions. We perform a first-principles calculation of the Electron-Phonon Interaction in phosphorene based on density functional perturbation theory and Wannier interpolation. Our calculation reveals that (1) the high anisotropy provides extra phase space for Electron-Phonon scattering, and (2) optical phonons have appreciable contributions. Both effects cannot be captured by the deformation potential calculations. Our simulation predicts carrier mobilities ∼170 cm 2 /V s for both electrons and holes at 300 K, and a thermoelectric figure of merit zT of up to 0.14 in p-type impurity-free phosphorene at 500 K.
G Benedek - One of the best experts on this subject based on the ideXlab platform.
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origin of the electron phonon Interaction of topological semimetal surfaces measured with helium atom scattering
Journal of Physical Chemistry Letters, 2020Co-Authors: G Benedek, J R Manson, Salvador Miretartes, Adrian Ruckhofer, Wolfgang Ernst, Anton TamtoglAbstract:He atom scattering has been demonstrated to be a sensitive probe of the Electron-Phonon Interaction parameter λ at metal and metal-overlayer surfaces. Here it is shown that the theory linking λ to the thermal attenuation of atom scattering spectra (the Debye-Waller factor) can be applied to topological semimetal surfaces, such as the quasi-one-dimensional charge-density-wave system Bi(114) and the layered pnictogen chalcogenides. The Electron-Phonon coupling, as determined for several topological insulators belonging to the class of bismuth chalcogenides, suggests a dominant contribution of the surface quantum well states over the Dirac electrons in terms of λ.
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theory of atom scattering from surface phonon the role of electron phonon Interaction
2018Co-Authors: G Benedek, J P ToenniesAbstract:The forces that an He atom exerts on the atoms of a solid surface causing inelastic scattering have much in common with the interatomic forces that govern the dynamics of the lattice. The scattering theory, described in Chap. 7 based on two-body collisions, provides the correct interpretation of data for closed-shell surfaces, much as their lattice dynamics is well described by phenomenological interatomic potentials. The inelastic HAS experiments from metal surfaces, however, cannot be successfully described in the same way. In this Chapter the approaches developed for the lattice dynamics of metals, where the interatomic forces are mediated by free electrons, such as the Multipole Expansion (ME) and the Density Functional Perturbation Theory (DFPT) are introduced for the analysis of inelastic HAS intensities from metal surfaces. These theories have the important consequences that inelastic HAS intensities are directly proportional to the Electron-Phonon coupling strength for individual phonons and that HAS can detect deep sub-surface phonons. The propensity of HAS to excite certain phonons of conducting surfaces rather than others is found to depend on the Electron-Phonon Interaction and the surface electron band structure.
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the electron phonon Interaction at deep bi 2 te3 semiconductor interfaces from brillouin light scattering
Scientific Reports, 2017Co-Authors: M Wiesner, A Trzaskowska, B Mroz, Sophie Charpentier, Sizhong Wang, Yuxin Song, Floriana Lombardi, P Lucignano, G BenedekAbstract:It is shown that the Electron-Phonon Interaction at a conducting interface between a topological insulator thin film and a semiconductor substrate can be directly probed by means of high-resolution Brillouin light scattering (BLS). The observation of Kohn anomalies in the surface phonon dispersion curves of a 50 nm thick Bi2Te3 film on GaAs, besides demonstrating important Electron-Phonon coupling effects in the GHz frequency domain, shows that information on deep interface electrons can be obtained by tuning the penetration depth of optically-generated surface phonons so as to selectively probe the interface region, as in a sort of quantum sonar.
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phonons and electron phonon Interaction at the sb 111 surface
Physical Review B, 2012Co-Authors: Davide Campi, G Benedek, M BernasconiAbstract:The bulk and surface dynamics of Sb(111) and the corresponding Electron-Phonon Interaction have been calculated by density functional perturbation theory. The surface phonon bands reveal features related to a remarkable stiffening of the surface bilayer with respect to the bulk ones. The main contribution to Electron-Phonon Interaction involves transitions between surface and bulk states, mostly driven by bulk phonons, and is found to be in good agreement with the value derived from spin angle-resolved photoemission spectroscopy.