Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Ultra-fast relaxation of electrons in wide-gap dielectrics   Low-energy electrons scattered in the conduction band of a dielectric solid
should behave like Bloch electrons and will interact with perturbations of the
atomic lattice, i.e. with phonons. Thus the phonon-based description of
low-energy scattering within an energy band structure of a solid bears certain
advantages against common free-electron scattering mechanisms. Moreover, the
inelastic scattering is described by the dielectric energy loss function. With
these collective scattering models we have performed the simulation of excited
electron relaxation and attenuation in the insulator SiO2. After excitation to
a mean initial energy of several eV their energy relaxation occurs within a
short time interval of 200 fs to full thermalization. There is a very rapid
impact ionization cooling connected with cascading of electrons at the
beginning during the first 10 fs, followed by much slower attenuation due to
phonon losses in wide-gap dielectrics and insulators.

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The categories of this paper are: acc-phys
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The categories of this paper are: astro-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: chao-dyn
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The categories of this paper are: funct-an
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The categories of this paper are: bayes-an
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The categories of this paper are: stat
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The categories of this paper are: nlin
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The categories of this paper are: plasm-ph
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The categories of this paper are: econ
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The categories of this paper are: chem-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: q-fin
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The categories of this paper are: math-ph
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The categories of this paper are: math
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The categories of this paper are: hep-th