The electronphonon interaction in metals selected topics in solid. It determines the electrical and thermal conductivity at ordinary temperatures and is the source of thermoelectric effects at high and low temperatures. We report ab initio study of the electronphonon coupling in a free standing beryllium monolayer. Their lattice dynamics and selfconsistently screened. Electron phonon coupling strength at metal surfaces directly.
Then we looked just at the ions, and discussed the lattice vibrations phonons while ignoring the existence of valence electrons apart from. Corrections to the electronic heat capacity of metals due to. The electronphonon interaction in metals selected topics. Thermoelectric power and electronphonon enhancement in. Pdf the electronphonon interaction in metals researchgate. Interplay between electron phonon and coulomb interactions in cuprates 3 energy and kresolution that can now be obtained in arpes, a lot of interest has focused on arpes recently, and we address these issues below. This hamiltonian was derived in chapter 1, with the form of the interaction given in sec. Because of the strong localization of the wave function it is reasonable to introduce the nearest.
While the electronphonon interaction has been studied for almost a century, predictive nonempirical calculations have become feasible only during the past two decades. Electronphonon coupling epc also provides in a fundamental way an attractive electronelectron interaction, which is always present and, in many metals, is the origin of the. Grimvall, the electronphonon interaction in metals, selected topics in solid state physics, editor e. Electronphonon coupling and electron heat capacity of metals. The electronphonon interaction is described by the vertex which represents scattering of an electron or hole by emission or absorption of a phonon or creation of an electron and hole by absorption of a phonon by an electron in the fermi sea. Buy the electronphonon interaction in metals selected topics in solid state physics xvi on free shipping on qualified orders. Electron phonon interactions an overview sciencedirect. Article pdf available january 1955 with 1,696 reads. The dependence of the strength of the electron phonon coupling and the electron heat capacity on the electron temperature is investigated for eight representative metals, al, cu, ag, au, ni, pt, w, and ti, for the conditions of strong electron phonon nonequilibrium. Nonrigidmuffintin calculations of the electronphonon. In chap ter 5 we will consider the contribution to the en tropy of metals at intermediate tempera. The electronphonon interaction and melting of metals. Volume 16 of selected topics in solid state physics.
The emphasis is on the electronphonon mass enhancement parameter the occurrence or absence of renormalization effects is discussed for different electronic properties. Electron phonon interactions so far, we considered the motion of electrons in the static periodic potential that would arise if the ions were frozen in their equilibrium positions. Volume 16 of science education and future human needs series. Electronphonon coupling epc also provides in a fundamental way an attractive electronelectron interaction, which is always present and, in many metals, is the origin of the electron pairing underlying the macroscopic quantum phenomenon of superconductivity. Electron phonon coupling epc also provides in a fundamental way an attractive electron electron interaction, which is always present and, in many metals, is the origin of the electron pairing underlying the macroscopic quantum phenomenon of superconductivity. On the polarization vectors of lattice vibrations grimvall. This lecture addresses the consequences of electron phonon coupling in both the. In the bulk the electronphonon coupling constant is grimvall, 1981. Thermochimica acta, 218 1993 116 elsevier science publishers b. The electronphonon interaction in metals 1981 edition.
Theoretical studies on the deformation potential, electron. Influence of hot electron scattering and electronphonon. Due to the small heat capacity of the electrons in metals and the. The ingredients necessary for a good description of the electronphonon interaction in simple metals are discussed from the point of view of lattice dynamics and electron transport.
On calculating the electronphonon mass enhancement. Early approaches to the electronphonon interaction. Lattice vibrations cause perturbations about equilibrium. Various electronphonon interactions such as the polar and nonpolar optical phonons, acoustic phonons that interact via deformation potential and via the piezoelectric effect and phonons in metals, are treated in this monograph by a single, relatively simple classical model. The frohlich hamiltonian describes the interaction between a single electron in a. Lenin state teaching institute, moscow submitted 3 november 1986 zh. The calculations were carried out using a linearresponse approach in the planewave pseudopotential representation. Electronphonon mass enhancement in metal multilayers. Electronphonon coupling and electron heat capacity in metals.
The electronphonon interaction in normal metals g grimvall electron tunnelling spectroscopy e l wolf a simple theory of the electronphonon mass enhancement in transition metals r evans, g d gaspari and b l gyorffy the electronic structure and its relationship to superconductivity in nih m gupta and j p burger on calculating the electron. Electronphonon interactions and related physical properties. Two aspects of electronphonon interaction bayo lau i. The foundations of the dynamics of condensed media, including surface vibrations and localization of phonons. The electronphonon interaction in metals selected topics in solid state physics xvi hardcover 1981. Electronphonon coupling and electron heat capacity of. The second reason for the traditional disregard of the electronphonon interactions is that the strength of these interactions has been thought to be small, at least with respect to the energies of the electrons involved, as measured by, say, some coupling constant in a perturbation theory formalism. However, the electronphonon interaction is important for other systems. Prominent among these e ects is supercon ductivity. The effect of the electronphonon interaction of the. He atom scattering has been demonstrated to be a sensitive probe of the electronphonon interaction parameter.
The interaction of the conduction electrons with the lattice vibrations is at the center of the whole theory of the transport properties of solids. Electronphonon interaction in a free standing beryllium monolayer a. Volume 16 of series of monographs on selected topics in solid state physics. Economou department ofphysics, university ofathens, athens, greece d. Grimvall avlade studentexamen pa reallinjen vid hvitfeldtska hogre allmanna laroverk i goteborg 1959, blev civilingenjor i teknisk fysik vid chalmers tekniska hogskola cth 1963, disputerade 1969 vid cth for doktorsgraden i fasta tillstandets teori pa avhandlingen electrons and phonons in metals, och antogs dar samma ar som docent i fasta tillstandets teori. We do not distinguish vibrations in isolated molecules and phonons in periodic lattices. These conditions are characteristic of metal targets. Electrons in thermally vibrating lattices springerlink. In this paper, the question of whether the mass enhancement can be manipulated in multilayers of two metals. Electronphonon interactions metals electric properties. Arpes experiments strongly indicate that small polarons are formed for undoped. A simplified approach to the fermis golden rule with electron energy transitions between only three energy levels is adopted to derive an electronphonon diffuse mismatch model, that account for the electronphonon thermal boundary conductance at metalinsulator interfaces increases with electron temperature. The electronphonon interaction in metals goran grimvall.
The polarization vectors as well as the mass m in eqs 4 and 5 are those of the crystal cores. Pdf electronphonon interactions from first principles. Dermot co ey a dissertation submitted to the faculty of the graduate school of the state. The eliashberg spectral function a2fx and the electronphonon coupling parameter k are evaluated at the fermi level. Rigid muffintin approximation for the electronphonon. Electronphonon interaction in a free standing beryllium. Electronphonon interaction epi in metals is a subject of intensive. Effects of the electronphonon interaction in hexagonal close. The electronphonon interaction in metals selected topics in. Electronphonon coupling at metal surfaces chalmers university of.
Introduction to the electron theory of metals the electron theory of metals describes how electrons are responsible for the bonding of metals and subsequent physical, chemical and transport properties. Phonon coupling strength at metal surfaces directly determined from the helium atom scattering debye. Grimvall institute of theoretical physics, chalmers university of technology, goteborg, sweden. The electronphonon interaction in metals nicolas bock october 27, 2003 advisor. The electronphonon interaction also contributes to the selfenergy of an electron.
The electron phonon interaction also contributes to the selfenergy of an electron. Armstrong ibm scientific center, palo alto, ca 94304, usa keywords. Electron phonon scattering electron phonon scattering finish lundstrom chapter 2 deformation potentials the mechanism of electron phonon coupling is treated as a perturbation of the band energies due to the lattice vibration. Electron phonon coupling strength at metal surfaces. Electronphonon coupling in the surface electronic states on pd111. Interplay between electronphonon and coulomb interactions in.
Melting, uncertainty principle, lindemann law, electron phonon interaction. This dependence is usually not an important aspect of photoemission in simple metals. On calculating the electronphonon mass enhancement lambda. Zdetsis department ofphysics, university of crete, crete, greece e. Effects of the electron phonon interaction in hexagonal closepacked metals by paul thomas truant, b. The electron phonon interaction is expanded in powers of the in teraction which involv es the singleion potential of the electrons in the potential of the ions. The study was guided by the course instructor prof. Today it is possible to calculate from first principles many materials properties related to the. Starting from a manybody theory expression for the entropy, this paper. Corrections to the electronic heat capacity of metals due. The emphasis is on the electronphonon mass enhancement parameter 1.
The effect of the electronphonon interaction of the conductivity of impure metals m. The electronphonon interaction also contributes to thermodynamic prop erties. A thesis submitted to the school of graduate studies. However, the electron phonon interaction is important for other systems. A simplified approach to the fermis golden rule with electron energy transitions between only three energy levels is adopted to derive an electronphonon diffuse mismatch model, that account for the electronphonon thermal boundary conductance at metal insulator. This textbook gives a complete account of electron theory in both periodic and nonperiodic metallic systems. Thermoelectric power and electronphonon enhancement in yba 2. Papaconstantopoulos naval research laboratory, washington, d. Using the ab initio anisotropic eliashberg theory including coulomb interactions, we investigate the electronphonon interaction and the pairing mechanism in the recentlyreported superconducting. While the electron phonon interaction has been studied for almost a century, predictive nonempirical calculations have become feasible only during the past two decades. Sichkar, theory of phononelectron interaction in metals, usp. Kadanofst department of ihysics, university of illinois, urbana, illinois received 15 october 1963. Origin of the electronphonon interaction of topological.
View the article online for updates and enhancements. Prangz department of pzysics and astronomy, unieerszty of maryland, college park, biaryland and leo p. Electronphonon interaction epi is one of the most important manybody interactions in condensedmatter and molecular systems, 1 1. A strong electronphonon interaction in a metal increases the electron density of states in the vicinity of the fermi energy dramatically. In the table below you can find files with tabulated data on the temperature dependences of the electron heat capacity and the electron phonon coupling factor, given for a range of electron temperatures that are typically realized in femtosecond laser processing of materials. This phenomenon is called electronphonon mass enhancement. The full text of this article hosted at is unavailable due to technical difficulties. Method the central problem in calculating the electronphonon interaction is the evaluation of changes in the electronic hamiltonian caused by atomic displacements. The lo phonons are usually represented by an einstein model, i. Electronphonon scattering finish lundstrom chapter 2.
At high temperatures this enhancement vanishes, but the electronphonon interaction gives the electrons a finite lifetime. This is followed by papers from international specialists studying a variety of theoretical and experimental problems. The temperature dependence of the thermopower is modified by the electronphonon interaction, and provides a means of estimating the strength of the interaction. Electronphonon interaction and pairing mechanism in. The recent discovery of hightemperature oxide superconductors14 has generated enormous interest both among physicists and, because of their obvious technological importance, in the wider. The electronphonon interaction in normal metals iopscience. The electronphonon interaction in metals sole distributors for the u. Electronphonon interactions so far, we considered the motion of electrons in the static periodic potential that would arise if the ions were frozen in their equilibrium positions. Volume 16 of studies in mathematical and managerial economics. The electronphonon interaction in electrondoped singlelayer mos2 was investigated using 1stprinciples calcns. When split in this way, the interaction term represents the interactions of the electrons and the quanta of the lattice vibrations, the phonons. Hamiltonian the basic interaction hamiltonian is hh h h pe ei 12 pq qq q haa 2 11 2 22 i e iijij p he mr ei i ei i j iij hvr vrr taylor series expansion for the displacements the electron. Effects of the electronphonon interaction in hexagonal.
The electron phonon interaction is expandedinpowersof the interaction whichinvolves the singleion potential of the electrons in the potential of the ions. Exchange and correlation effects in the electron gas are summarized and it is concluded that the local density approximation is satisfactory, as is rasolts. They can be viewed as bosonic particles which propagate through the crystal and interact with electrons. Berciu, who has been really generous with her time.
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