Electron-phonon coupling of epigraphene at millikelvin temperatures measured by quantum transport thermometry

We investigate the basic charge and heat transport properties of charge neutral epigraphene at sub-kelvin temperatures, demonstrating a nearly logarithmic dependence of electrical conductivity over more than two decades in temperature. Using graphene's sheet conductance as an in situ thermometer, we present a measurement of electron-phonon heat transport at mK temperatures and show that it obeys the T-4 dependence characteristic for a clean two-dimensional conductor. Based on our measurement, we predict the noise-equivalent power of similar to 10 - 22 W / Hz of the epigraphene bolometer at the low end of achievable temperatures.

Automated summary

This study examines the basic charge and heat transport properties of charge-neutral epigraphene at sub-kelvin temperatures, revealing a nearly logarithmic dependence of electrical conductivity over a wide temperature range. By using graphene's sheet conductance as an in-situ thermometer, the researchers demonstrated electron-phonon heat transport at millikelvin temperatures following the T-4 dependence of a clean two-dimensional conductor. Based on their measurements, they predict the noise-equivalent power of epigraphene bolometers to be around 10^-22 W/Hz at very low temperatures.