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Main Authors: Jain, A. K., Nicholls, J. T., Holmes, S. N., Jaliel, G., Chen, C., Farrer, I., Ritchie, D. A.
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2508.14694
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author Jain, A. K.
Nicholls, J. T.
Holmes, S. N.
Jaliel, G.
Chen, C.
Farrer, I.
Ritchie, D. A.
author_facet Jain, A. K.
Nicholls, J. T.
Holmes, S. N.
Jaliel, G.
Chen, C.
Farrer, I.
Ritchie, D. A.
contents We present measurements of the cooling length $\ell_E$ for hot electrons in a GaAs-based high mobility two-dimensional electron gas (2DEG). The thermal measurements are performed on a long 60 $μ$m-wide channel, which is Joule-heated at one end, along which there are three similar hot-electron thermocouples, spaced 30 $μ$m apart. The thermocouples measure an exponentially decaying temperature profile with a characteristic length $\ell_E$, which decreases from 23 to 16 $μ$m as the lattice temperature increases from 1.8 to 5 K. From a simple one-dimensional model of heat diffusion, we measure an inelastic scattering time which decreases from $τ_i \approx$ 0.36 to 0.18 ns. The measured $τ_i$ has a magnitude and temperature dependence consistent with acoustic phonon scattering times. We discuss how the sample design can be varied for further thermal investigations. Knowledge of the temperature profile and its gradient will prove useful in measurements of the thermal conductivity and the Nernst effect.
format Preprint
id arxiv_https___arxiv_org_abs_2508_14694
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle The heating and cooling of 2D electrons at low temperatures
Jain, A. K.
Nicholls, J. T.
Holmes, S. N.
Jaliel, G.
Chen, C.
Farrer, I.
Ritchie, D. A.
Mesoscale and Nanoscale Physics
We present measurements of the cooling length $\ell_E$ for hot electrons in a GaAs-based high mobility two-dimensional electron gas (2DEG). The thermal measurements are performed on a long 60 $μ$m-wide channel, which is Joule-heated at one end, along which there are three similar hot-electron thermocouples, spaced 30 $μ$m apart. The thermocouples measure an exponentially decaying temperature profile with a characteristic length $\ell_E$, which decreases from 23 to 16 $μ$m as the lattice temperature increases from 1.8 to 5 K. From a simple one-dimensional model of heat diffusion, we measure an inelastic scattering time which decreases from $τ_i \approx$ 0.36 to 0.18 ns. The measured $τ_i$ has a magnitude and temperature dependence consistent with acoustic phonon scattering times. We discuss how the sample design can be varied for further thermal investigations. Knowledge of the temperature profile and its gradient will prove useful in measurements of the thermal conductivity and the Nernst effect.
title The heating and cooling of 2D electrons at low temperatures
topic Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2508.14694