This work demonstrated unprecedented quantitative accuracy over a wide temperature range with no adjustable parameters and has since inspired a plethora of ab initio phonon transport calculations for a variety of systems metals, semiconductors, and insulators in one, two, and three dimensions, providing further validation, making new. This lecture addresses the consequences of electron phonon coupling in both the. The aim of this paper is to provide a comprehensive ab initio analysis of the electronic structure, lattice dynamics, and electronphonon coupling of surface electronic states for the bi111 surface. Abstract we study the electronphonon coupling strength near the interface of monolayer and bilayer fese thin films on srtio 3, batio 3, and oxygenvacant srtio 3 substrates, using ab initio methods. The calculations based on densityfunctional theory. Ab initio calculation of electronphonon coupling in.
Electronphonon eph interactions are usually treated in the lowest order of. Ab initio electrontwophonon scattering in gaas from next. Electronphonon eph interactions are usually treated in the lowest. We present an ab initio study of the electronphonon interaction in the surface electronic states on pd111. The school addresses senior phd students and experienced researchers with prior working knowledge of dft. We determine the strength of the electronphonon interaction using the vienna abinitio simulation program vasp 3 with the small displacement method. Pdf ab initio determination of effective electronphonon. Abinitio approaches based on dft and nonequilibrium greens. We describe the ab initio nonequilibrium greens function method for electrontransport calculations in nanoscale devices based on the efficient molecularorbital approach. The electron electron interaction is also renormalized by the electron phonon coupling. We perform a firstprinciples calculation of the electron phonon interaction in phosphorene based on density functional perturbation theory and wannier interpolation.
The perturbation of the electronic energies due to the atomic distortion caused by totally symmetric phononswas calculated, yielding the matrix elements of the electron phononinteraction. I led an extensive verification and validation study of the theory and software implementations of the temperaturedependence of. Ab initio optimization of phonon drag effect for lower. Ab initio study of the electronphonon coupling at the cr. School on electronphonon physics from first principles. Ab initio phonon coupling and optical response of hot electrons in plasmonic metals ana m. School on electronphonon physics from first principles psik. Ab initio calculation of spindependent electronphonon coupling in iron and cobalt 2 1. Unfortunately, introducing so interaction into ab initio namd is not an easy task. The epw electron phonon coupling using wannier functions software is a fortran90 code that uses densityfunctional perturbation theory and maximally localized wannier functions for computing electron phonon couplings and related properties in solids accurately and efficiently. Relativistic corrections due to spinorbit coupling are co. Modelling materials with ab initio electronic structure.
Ab initio study of crossinterface electronphonon couplings. The obtained g eph is implemented into a molecular dynamics md and twotemperature model ttm coupled simulation of femtosecond laser. Ab initio electrondefect interactions using wannier. The perturbation of the electronic energies due to the atomic distortion caused by totally symmetric phononswas calculated, yielding the matrix elementsof the electron phononinteraction. Ab initio determination of effective electronphonon coupling. From 19th to 23rd march 2018 the first school entirely devoted to firstprinciples calculations of electron phonon interactions was held at the abdus salam international center for theoretical physics on the miramare seafront in trieste. We find substantial differences from free electron and semiempirical estimates, especially in noble metals above transient electron temperatures of 2000 k, because of the previously neglected. Mar 12, 2020 ab initio electrondefect interactions using wannier functions. Yet, experimentally measuring this coupling as a function of momentum and for a particular phonon mode is tricky. Ab initio calculation of spindependent electronphonon.
Aps aps march meeting 2018 event predictive ab initio. The calculated total electronphonon coupling strength. Lif and mgo, presenting for the first time, their full ab initio electron phonon spectral function 11. Electronphonon coupling from ab initio linearresponse theory within the gw method. Electronphonon coupling in the surface electronic states on pd111. Rudin department of physics, georgetown university, washington, d. Ab initio calculations of the crystal field and phonon. We study the electronphonon coupling strength near the interface of monolayer and bilayer fese thin films on srtio 3, batio 3, and oxygenvacant srtio 3 substrates, using ab initio methods. The coupling between electrons and phononslattice vibrations in solidsis responsible for macroscopic quantum phenomena such as superconductivity. Ab initio electron phonon interactions using atomic orbital. Ab initio study of electronphonon inter action in phosphorene. In our work, effective deformation potentials usually used in the framework of conwells model.
Crossover from lattice to plasmonic polarons of a spinpolarised. The crystal structure of mapbi 3 shows strong temperature dependence. Direct determination of modeprojected electronphonon. The ab initio calculations where electrons are treated in the localdensity approximation, and phonons and the electron phonon interaction are treated within linear response. Abinitio description of phase transitions in tio2 and ab. Ab initio study of electronphonon inter action in phosphorene the mit faculty has made this article openly available. Ab initio lattice dynamics and electronphonon coupling of bi. Correlationenhanced interactions and superconductivity in ba1xkxbio3 zhenglu li, gabriel antonius, meng wu, felipe h. Ab initio calculation of electronphonon coupling in monoclinic bga 2o 3 crystal krishnendu ghosha and uttam singisettib electrical engineering department, university at buffalo, buffalo, new york 14260, usa. The purpose of this school was to offer training into ab initio calculations of many properties relating to the electronphonon interaction, with a focus on applications in condensed matter physics, materials physics, and nanoscience. Mar 30, 2020 in materials with intermediate or strong eph coupling. Ab initio descriptions of these phenomena are far behind those given for electron phonon coupling. The use of ab initio methods for accurate simulations of electronic, phononic, and electronphonon properties of molecular materials such as organic crystals is a challenge that is often tackled stepwise based on molecular properties calculated in gas phase and perturbatively treated parameters relevant for. During the transport of the absorbed thermal energy from electron subsystem to lattice subsystem, the electronphonon coupling factor.
Ab initio electrontwophonon scattering in gaas from nextto. Ab initio electronphonon interactions using atomic orbital. Modelling materials with ab initio electronic structure software castep. In this paper we examine the electron phonon coupling of the cr001 surface by means of ab initio calculations in the form of density functional perturbation theory. Strong electron phonon coupling and ab initio theory of heat transport. I am the lead developer of the electron phonon wannier epw software package 16 and i amwas also actively involved in the development of the quantum espresso. Jinjian zhou, jinsoo park, ite lu, ivan maliyov, xiao tong, marco bernardi, perturbo.
These conditions are characteristic of metal targets. Ab initio calculation of spindependent electronphonon coupling in. Relativistic corrections due to spinorbit coupling are consistently taken into account. Gonze x et al 2005 a brief introduction to the abinit software project z. For larger momenta, the lower surface band exhibits a moderate electronphonon coupling of about 0. Apr 28, 2015 our computed electronphonon relaxation times at the onset of the.
Chlorine doping reduces electron hole recombination in. To extend these coupled transport descriptions to such cases will. Electronphonon eph scattering due to lo modes, and in general to polar phonons pps, is typically the main carrier scattering mechanism in polar materials, but it cannot yet be included in ab initio transport calculations. The electron temperature t e dependent electron density of states g. Dec 20, 2019 ab initio modelling of advanced materials amm 2019 cpmd 2019 pushing the boundaries of molecular dynamics report. Electronphonon relaxation at auti interfaces is robust to alloying. The phonona software does not use the perturbatiion approach, but it applies an original way of probing the atomic patterns arrising during anharmonic displacements. Software for calculating harmonic and anharmonic lattice dynamics of crystals. A specially important is the appearence of electronphonon coupling effect. Ab initio calculation of spindependent electronphonon coupling in iron and cobalt. Brown, 1ravishankar sundararaman, 2prineha narang,3 william a. Dr hasnip is a theoretical physicist and research software engineer and a lead author of the castep program.
Ab initio approaches based on dft and nonequilibrium greens. I am the lead developer of the electronphonon wannier epw software package 16 and i amwas also actively involved in the development of the quantum espresso qe 21, wannier90 33 and abinit 15 codes. He has over 20 years experience in ab initio materials modelling, with a particular interest in creating efficient, userfriendly software tools to aid experimental research. Ab initio phonon coupling and optical response of hot. Recently we developed an ab initio greenkubo approach based on the local representation of the stress tensor together with an. We present a comprehensive ab initio study of structural, electronic, lattice dynamical and electron phonon coupling properties of the bi111 surface within density functional perturbation theory. Published 1 march 20 20 iop publishing ltd journal of physics. Strong electronphonon coupling and ab initio theory of.
Ab initio and molecular dynamics predictions for electron and phonon transport in bismuth telluride baoling huang and massoud kaviany department of mechanical engineering, university of michigan, ann arbor, michigan 481092125, usa. Using indium as a test case, we investigate the accuracy of the electron phonon coupling calculated with stateoftheart ab initio and manybody theory methods. For some values of the electron phonon coupling constants, the renormalized coulomb integrals can be negative resulting in the. Electronphonon scattering plays a decisive role in electron transport and is taken into account in ab initio calculations by leadingorder perturbations involving scattering events with one phonon. Electronphonon coupling from ab initio linearresponse. Electronphonon coupling cannot be taken into account explicitly. We present a comprehensive ab initio study of structural, electronic, lattice dynamical, and electron phonon coupling properties of the bi111 surface within density functional perturbation theory. More precisely, the electron phonon massenhancement factor of the surface layer is investigated for the 3d states.
Ga2o3 gives rise to 30 phonon modes all of which are taken into account in transport calculation. Psik cecam workshop in lugano on electronphonon coupling. Ab initio study of electronphonon interaction in phosphorene. However, the large nonequilibrium between the electronic and phononic subsystems. Citation liao, bolin, jiawei zhou, bo qiu, mildred s. Aug 15, 2016 the interaction between electrons and vibrational modes in monoclinic. Psik cecam workshop in lugano on electron phonon coupling. We predict that pressurized, semimetallic uo2 is a relatively sluggish conductor due to its strong electron phonon coupling. Abstract we demonstrate the ab initio electrical transport calculation limited by electronphonon coupling by using the full solution of the boltzmann transport equation bte, which applies equally to metals and semiconductors. Results of ab initio calculation of electronphonon interaction in laser cooling are reported and compared with the values estimated using analytical harmonic potential approximation. Ab initio determination of effective electronphonon coupling factor in copper pengfei ji and yuwen zhang1 department of mechanical and aerospace engineering university of missouri columbia, mo 65211, usa abstract the electron temperature dependent electron density of states, fermidirac. 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. Bernardi ab initio electron phonon interactions using atomic orbital wavefunctions. The ab initio calculation of the electronphonon coupling parameter for an amorphous system is problematic due to the needed size of the supercell.
We demonstrate the ab initio electrical transport calculation limited by electronphonon coupling by using the full solution of the boltzmann transport equation bte, which applies equally to. Ab initio electron mobility and polar phonon scattering in gaas. Electron phonon scattering in the presence of soft modes and electron mobility in srtio3 perovskite from first principles. Ab initio study of electronphonon coupling in rubrene.
Ab initio calculation of electronphonon coupling in monoclinic. Indium as a test case for ab initio and manybody theory methods sven p. Ab initio description of transport in nanostructures. Note, that we use the electronphonon coupling as a free parameter to adapt to experimental results. The calculations were performed using the opensource software. Ab initio descriptions of these phenomena are far behind those given for electronphonon coupling. Other descriptions may include static and dynamic interactions with electric, magnetic, and electromagnetic fields and their resulting excitationsexcitons, polaritons, etc. Electronphonon coupling from ab initio linearresponse theory. Electronic bandstructure changes due to normalmode ligand displacement are used to.
Furthermore, we plan to adapt the electronphonon coupling to the experiment. Ab initio studies of electronphonon coupling in single. Ab initio and molecular dynamics predictions for electron. Survey of ab initio phonon thermal transport sciencedirect. Ab initio electron propagators in molecules with strong. For the purpose of comparison, the experimental result and ab initio calculation result are plotted in fig. The spindependent electronphonon coupling has been calculated ab initio in bcc iron and hcp cobalt, and compared to a range of available experimental data. By monitoring temperature evolutions of electron and lattice subsystems, the result utilizing coupling factor from ab initio calculation, shows a faster decrease of electron temperature and increase of. Ab initio determination of effective electron phonon coupling factor in copper. Jun 21, 2007 ab initio electron propagators in molecules with strong electronphonon interaction. The calculated phonon band structures are very accurate. Electronphonon coupling and electron heat capacity of metals.
Ultrafast laser measurements probe the nonequilibrium dynamics of excited electrons in metals with increasing temporal resolution. Ab initio determination of effective electronphonon. Though you have some ways to go beyond the harmonic approximation, it depends on your problem. Calculation of electronphonon interaction strength from first.
We perform a firstprinciples calculation of the electronphonon interaction in phosphorene based on density functional perturbation theory and wannier interpolation. The epw electronphonon coupling using wannier functions software is a fortran90 code that uses densityfunctional perturbation theory and maximally localized wannier functions for computing electronphonon couplings and related properties in solids accurately and efficiently. For more details on the code structure of perturbo, we refer the users to the manuscript accompying the source code. Our calculation reveals that 1 the high anisotropy provides extra phase space for electron phonon scattering, and 2 optical phonons have appreciable contributions.
We present ab initio calculations of electron phonon coupling in singlewalled nanotubes and graphene. Taken together, perturbo provides efficient and broadly applicable ab initio tools to investigate electronphonon interactions and carrier dynamics quantitatively in metals, semiconductors, insulators, and 2d materials. The ab initio investigation of electron phonon interaction is carried out by using the density function theory dft code abinit. Ga2o3 is theoretically investigated using ab initio calculations. Ab initio modelling of advanced materials amm 2019 cpmd 2019 pushing the boundaries of molecular dynamics report. Ab initio calculations of the crystal field and phonon dispersions in. Dec 01, 2015 ab initio optimization of phonon drag effect for lowertemperature thermoelectric energy conversion. Electronphonon relaxation at auti interfaces is robust. Theoretical and handson training will focus on ab initio calculations of many properties relating to the electron phonon interaction, for applications in condensed matter physics, materials physics, and nanoscience. However, an ab initio theory that can describe materials belonging to the whole range of such thermal conductivities was lacking so far. 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. Feb 06, 2020 perturbo is a software package for firstprinciples calculations of charge transport and ultrafast carrier dynamics in materials. The current version focuses on electronphonon interactions and can compute phononlimited transport properties such as the conductivity, carrier mobility and seebeck coefficient.
Electrical transport limited by electronphonon coupling. I will describe our implementation of the boltzmann formalism within the electronphonon software package epw 1, and discuss the computational challenges associated with the evaluation of the scattering integrals, the singular behavior of frohlich polar electronphonon coupling at long wavelengths 2,3, and the necessity to include many. The team has also made significant technical developments including hybrid openmpmpi parallelism and porting to. A specially important is the appearence of electronphonon coupling effect related also to anharmonicity. It can also simulate the ultrafast nonequilibrium electron dynamics in the presence of. Watson laboratories of applied physics, california institute of technology, pasadena, california 91125, usa. Ab initio electron propagators in molecules with strong electronphonon interaction. The finite temperature density functional formalism proposed by mermin is utilized to represent the different degrees of electron excitation at given t e. Our calculation reveals that 1 the high anisotropy provides extra phase space for electronphonon scattering, and 2 optical phonons have appreciable contributions. The electronphonon interaction is calculated under density functional perturbation theory and then interpolated using wannier. We present ab initio predictions of the electron temperature dependent heat capacities and electron phonon coupling coefficients of plasmonic metals.
Ab initio lattice dynamics and electronphonon coupling of. Ab initio electron defect interactions using wannier functions. Ab initio study of electronphonon coupling and excitonic. Ab initio phonon coupling and optical response of hot electrons in plasmonic metals.