Microwave noise thermometry of graphene/α-RuCl₃ heterostructures

Recently, we discovered a strong charge transfer between graphene and the layered Mott insulator α-RuCl₃, which yields hole densities as large as a few 10¹³ cm^-2 in graphene and is tunable by modulating the graphene-RuCl₃ separation with an insulating spacer. Beyond the potential for applications of graphene devices having tunable and patterned potential profiles, the charge transfer makes graphene a low-resistance electrical contact to α-RuCl₃, which may be useful for accessing its electronic and thermal properties. We present microwave Johnson-Nyquist noise thermometry measurements of graphene/α-RuCl₃ heterostructures to quantify the thermal transport mechanisms between graphene and α-RuCl₃, and demonstrate tunability of the coupling with interface separation. We will present details of the fabrication process and measurement setup and discuss how this technique may be useful for probing the thermal conductance of exfoliated α-RuCl₃.