Picosecond relaxation of X-ray excited GaAs

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389021%3A_____%2F17%3A00508745" target="_blank" >RIV/61389021:_____/17:00508745 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/68378271:_____/17:00487394

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/abs/pii/S1574181817300605?via%3Dihub" target="_blank" >https://www.sciencedirect.com/science/article/abs/pii/S1574181817300605?via%3Dihub</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.hedp.2017.05.012" target="_blank" >10.1016/j.hedp.2017.05.012</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Picosecond relaxation of X-ray excited GaAs

Popis výsledku v původním jazyce

In this paper we present the current status of our theoretical studies on ultrafast relaxation of X-ray/XUV excited gallium arsenide. First, we discuss our previous approach, the unified model based on rate equations, two-temperature model and the extended Drude approach. By fitting the model to the available experimental data, we obtained realistic estimates on transient electronic temperature and electron-lattice thermalization timescale. Next, we make a step towards a rigorous description of the relaxation process with our hybrid code, XTANT. We extend the XTANT to include the band-specific effect of the suppression of collisional processes in GaAs, and perform dedicated simulations. We find that the extended model correctly describes the predicted transient non-isothermality of conduction and valence bands, however, currently, it cannot reproduce the experimentally observed reflectivity overshooting at 5-10 ps. The reason for this discrepancy is that the electron-phonon coupling rate implemented in XTANT, although successfully applied for diamond and silicon, clearly underestimates the strength of this coupling in GaAs. The outline for a respective model improvement is discussed.

Název v anglickém jazyce

Picosecond relaxation of X-ray excited GaAs

Popis výsledku anglicky

In this paper we present the current status of our theoretical studies on ultrafast relaxation of X-ray/XUV excited gallium arsenide. First, we discuss our previous approach, the unified model based on rate equations, two-temperature model and the extended Drude approach. By fitting the model to the available experimental data, we obtained realistic estimates on transient electronic temperature and electron-lattice thermalization timescale. Next, we make a step towards a rigorous description of the relaxation process with our hybrid code, XTANT. We extend the XTANT to include the band-specific effect of the suppression of collisional processes in GaAs, and perform dedicated simulations. We find that the extended model correctly describes the predicted transient non-isothermality of conduction and valence bands, however, currently, it cannot reproduce the experimentally observed reflectivity overshooting at 5-10 ps. The reason for this discrepancy is that the electron-phonon coupling rate implemented in XTANT, although successfully applied for diamond and silicon, clearly underestimates the strength of this coupling in GaAs. The outline for a respective model improvement is discussed.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10306 - Optics (including laser optics and quantum optics)

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2017

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

High energy density physics

ISSN

1574-1818

e-ISSN

—

Svazek periodika

24

Číslo periodika v rámci svazku

September

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

7

Strana od-do

15-21

Kód UT WoS článku

000410831800003

EID výsledku v databázi Scopus

2-s2.0-85020308135