Electron Thermalization in Para-H₂ at Very Low Temperature

In this study, we investigate the thermalization length of quasifree electrons in a parahydrogen solid film (P-H<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>) at <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$T\approx 2.8K$</tex> using charge collection measurements. Electrons are injected into the system via the photoelectric effect, and their transport behavior is analyzed. The measured thermalization length <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$z_{0}=(26.1\pm 1.0)$</tex> nm is consistent with previous studies in different systems indicating that electron transport remains largely unhindered by short-range localization effects, although it exhibits rapid energy dissipation through electron-phonon interactions. These findings provide insights into charge transport mechanisms in quantum solids.