Ultrasensitive and Wide-Bandwidth Thermal Measurements of Graphene at Low Temperatures

摘要: Graphene is a material with remarkable electronic properties[1] and exceptional thermal transport properties near room temperature, which have been well examined understood[2, 3]. However at very low temperatures the thermodynamic transport properties are much less explored[4, 5] somewhat surprisingly, expected to exhibit extreme isolation. Here we demonstrate an ultra-sensitive, wide-bandwidth measurement scheme probe the thermal of electron gas graphene. We employ Johnson noise thermometry microwave frequency sensitively measure temperature the electron resolution 4mK/√Hz bandwidth 80 MHz. measured the electron-phonon coupling from 2-30 K charge density 2 •10^(11)cm^(-2). Utilizing bolometric mixing, sensed oscillations period 430 ps determined the heat capacity be • 10^(-21)J/(K •µm^2) 5 consistent that of two dimensional, Dirac gas. These measurements suggest that graphene-based devices together wide can generate substantial advances in the areas ultra-sensitive bolometry[6], calorimetry[7], terahertz photo-detection[8], and bolometric mixing for applications areas such as observational astronomy[9] quantum information measurement[10].