scispace - formally typeset
Search or ask a question
Topic

Free electron model

About: Free electron model is a research topic. Over the lifetime, 4678 publications have been published within this topic receiving 103535 citations.


Papers
More filters
Journal ArticleDOI
TL;DR: In this article, the thermoelectric Seebeck effect was used to estimate the electron effective mass (m*) in n-type carrier-induced ferromagnetic semiconductor (In,Fe)As.
Abstract: The electron effective mass (m*) in n-type carrier-induced ferromagnetic semiconductor (In,Fe)As was estimated by using the thermoelectric Seebeck effect. It was found that m* is 0.03 ∼ 0.17m0 depending on the electron concentration, where m0 is the free electron mass. These values are similar to those of electrons in the conduction band of n+ InAs. The Fermi level EF in (In,Fe)As is located at least 0.15 eV above the conduction band bottom. Our results indicate that electron carriers in (In,Fe)As reside in the conduction band, rather than in a hypothetical Fe-related itinerant impurity band.

59 citations

Journal ArticleDOI
TL;DR: In this article, the effect of volume and surface plasma excitation on the spectra of Ag(111) evaporated electrodes on mica in aqueous electrolytes was measured within the wavelength range of 500 to 200 nm for p- and s-polarized light as a function of the angle of incidence, bias potential and surface roughness.

58 citations

Journal ArticleDOI
TL;DR: In this article, a formula for the probability of stimulated emission of Bremsstrahlung is derived and it is shown that stimulated emission occurs if the incident electrons travel in a direction roughly parallel to the electric field vector of the wave stimulating the emission.
Abstract: A formula for the probability of stimulated emission of Bremsstrahlung is derived. It is shown that stimulated emission occurs if the incident electrons travel in a direction roughly parallel to the electric field vector of the wave stimulating the emission. Emission from free electrons is used in electron tube devices. The purpose of this paper is to show that stimulated emission occurs already in the elementary process of the encounter of one electron and one nucleus or ion. There is no need for a slow-wave structure or elaborate electron bunching and no need to consider phase relationships. This elementary effect of stimulated emission should lead to a type of oscillator and broadband amplifier working without slow-wave structures or need for the close mechanical tolerances of high-frequency klystrons. A device of this kind may be noisier than a conventional maser. It may be that the effect discussed in this paper is responsible for some of the hitherto unexplained semiconductor diode oscillations which have been reported in the literature.

58 citations

Journal ArticleDOI
TL;DR: In this article, a joint experimental and theoretical study on strong field photo-ionization of sodium atoms using chirped femtosecond laser pulses is presented, where different excitation pathways enabling control are identified by simultaneous ionization and measurement of photoelectron angular distributions employing the velocity map imaging technique.
Abstract: We present a joint experimental and theoretical study on strong- field photo-ionization of sodium atoms using chirped femtosecond laser pulses. By tuning the chirp parameter, selectivity among the population in the highly excited states 5p, 6p, 7p and 5f, 6f is achieved. Different excitation pathways enabling control are identified by simultaneous ionization and measurement of photoelectron angular distributions employing the velocity map imaging technique. Free electron wave packets at an energy of around 1eV are observed. These photoelectrons originate from two channels. The predominant 2+1+1 resonance enhanced multi-photon ionization (REMPI) proceeds via the strongly driven two-photon transition 4s 3s, and subsequent ionization from the states 5p, 6p and 7p whereas the second pathway involves 3+1 REMPI via the states 5f and 6f. In addition, electron wave packets from two-photon ionization of the non-resonant transiently populated state 3p are observed close to the ionization threshold. A mainly qualitative five-state model for the predominant excitation channel is studied theoretically to provide insights into the physical mechanisms at play. Our analysis shows that by tuning the chirp parameter the dynamics is effectively controlled by dynamic Stark shifts and level crossings. In particular, we show that under the experimental conditions the passage through

58 citations


Network Information
Related Topics (5)
Electron
111.1K papers, 2.1M citations
95% related
Excited state
102.2K papers, 2.2M citations
91% related
Band gap
86.8K papers, 2.2M citations
90% related
Scattering
152.3K papers, 3M citations
89% related
Magnetic field
167.5K papers, 2.3M citations
89% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202340
202290
2021132
2020122
2019114
2018112