Electronic Thermal Transport Measurement in Low-Dimensional Materials with Graphene Nonlocal Noise Thermometry

TL;DR

This paper introduces a nonlocal noise thermometry technique using graphene to measure electronic thermal conductance in low-dimensional materials, revealing insights into energy transport mechanisms with high precision.

Contribution

It presents a novel method for isolating and measuring electronic thermal conductance in low-dimensional systems using graphene-based noise thermometry.

Findings

Quantitative electronic thermal conductance measurements up to 70 K.

Achieved ~1% precision of the thermal conductance quantum at 5 K.

Observed signatures of long-range interaction-mediated energy transport.

Abstract

In low-dimensional systems, the combination of reduced dimensionality, strong interactions, and topology has led to a growing number of many-body quantum phenomena. Thermal transport, which is sensitive to all energy-carrying degrees of freedom, provides a discriminating probe of emergent excitations in quantum materials and devices. However, thermal transport measurements in low dimensions are dominated by the phonon contribution of the lattice, requiring an experimental approach to isolate the electronic thermal conductance. Here, we show how the measurement of nonlocal voltage fluctuations in a multiterminal device can reveal the electronic heat transported across a mesoscopic bridge made of low-dimensional materials. By using 2-dimensional graphene as a noise thermometer, we demonstrate quantitative electronic thermal conductance measurements of graphene and carbon nanotubes up to 70 K, achieving a precision of ~1% of the thermal conductance quantum at 5 K. Employing linear and nonlinear thermal transport, we observe signatures of long-range interaction-mediated energy transport in 1-dimensional electron systems, in agreement with a theoretical model. Our versatile nonlocal noise thermometry allows new experiments probing energy transport in emergent states of matter and devices in low dimensions.