Electron-Phonon Interactions

Bu çalışmada, elektronların akustik fononlar ile etkileşmesinden kaynaklanan kiral polaron oluşumu incelenmiştir. Elektron-fonon sistemlerinin taban durumunu hesaplayabilmek için Lee-Low-Pines teorisi çerçevesinde analitik bir metot geliştirilmiştir. Grafenin dejenere band yapısının kiral polaron oluşumunu desteklediği tespit edilmiştir.

The Heisenberg’s uncertainty principle can be obtained from the phonon dynamics as follows, from the basic assumptions, of the phonon theory, in a crystal, I have assumed that the atoms of the crystal are spherically symmetric as well as the charge distribution on the each of the atoms. Since there are attractive as well repulsive forces acting between the different atoms of a crystal, there might be a definite value of the potential due to this ‘interaction’.

This paper presents a theoretical model for the effect of electron-phonon interaction, temperature and magnetic field on degree of electron spin polarization in GaAs/InAs quantum dot LED. To describe the dynamics, quantum Langevin equation for photon number and carrier number is used. Simulation results show that degree of electron spin polarization in quantum dot decreases with increase of electron phonon interaction parameter at constant temperature and constant magnetic field which agrees with experimental results in literatures.

This paper presents a theoretical model for the effect of electron-phonon interaction, temperature and magnetic field on degree of electron spin polarization in GaAs/InAs quantum dot LED. To describe the dynamics, quantum Langevin equation for photon number and carrier number is used. Simulation results show that degree of electron spin polarization in quantum dot decreases with increase of electron phonon interaction parameter at constant temperature and constant magnetic field which agrees with experimental results in literatures.

... These two configurations are expected to have different behavior since, in the latter one, the axial symmetry is broken. We found the energy levels by solving numerically the BenDaniel-Duke equation [ −¯h2 2 ∇ · ( 1 m∗(x, y, z) ∇ ) + V(x, y, z) ] (x, y, z) = E (x, y, z), (1) ...

This  paper  presents  a  theoretical  model  for  the  effect  of  electron
-
phonon  interaction,  temperature  and
magnetic  field  on  degree  of  electron  spin  polarization  in  GaAs/InAs  quantum  dot  LED.  To  describe  the
dynamics,  quantum Langevin equation for photon numbe
r and carrier number is used. Simulation results
show that degree of electron spin polarization in quantum dot decreases with increase of electron phonon
interaction parameter at constant temperature and constant magnetic field which agrees with experiment
al
results in literatures.

Nanocomposites of linear chain of ferroelectric-ferromagnetic crystal structure is considered. It is analyzed theoretically in the motion equation method on the pursuit of magnonic excitations,lattice vibration excitations and their interactions leading to a new collective mode of excitations,the electormagnons. In this particular work, it is observed that the magnetizations and polarizations are tunable in a given temperature ranges for some specific values of the coupling order parameter.

We study the electron and phonon thermal coupling mechanisms at interfaces between gold films with and without Ti adhesion layers on various substrates via pump-probe time-domain thermoreflectance. The coupling between the electronic and the vibrational states is increased by more than a factor of five with the inclusion of an 3 nm Ti adhesion layer between the Au film and the nonmetal substrate. Furthermore, we show an increase in the rate of relaxation of the electron system with increasing electron and lattice temperatures induced by the laser power and attribute this to enhanced electron-electron scattering, a transport channel that becomes more pronounced with increased electron temperatures. The inclusion of the Ti layer also results in a linear dependence of the electron-phonon relaxation rate with temperature, which we attribute to the coupling of electrons at and near the Ti/substrate interface. This enhanced electron-phonon coupling due to electron interface scattering is shown to have negligible influence on the Kapitza conductances between the Au/Ti and the substrates at longer time scales when the electrons and phonons in the metal have equilibrated. These results suggest that only during highly nonequilibrium conditions between the electrons and phonons (Te >> Tp) does electron-phonon scattering at an interface contribute to thermal boundary conductance.