Electronic thermal transport measurement in low-dimensional materials with graphene non-local noise thermometry

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. However, thermal transport measurements in low dimensions are dominated by the phonon contribution of the lattice. An experimental approach to isolate the electronic thermal conductance is needed. 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 graphene as a noise thermometer, we demonstrate quantitative electronic thermal conductance measurements of graphene and carbon nanotubes up to 70K, achieving a precision of ~𝟏% of the thermal conductance quantum at 𝟓𝐊.

Nonlocal thermoelectric resistance in vortical viscous transport

“…We highlight that high-resolution thermal imaging and scanning gate microscopes [40,41] and Johnson-Nyquist nonlocal noise thermometry [42,43] may provide exquisite tools to probe viscous electron vorticity in parameter domains where these signatures are no longer present in the charge transport mode.…”

Hydrodynamic electron transport in graphene Hall-bar devices

“…The results of this section can be tested by spaceresolving probes of hydrodynamic electron transport in graphene, e.g. in a measurement based on the nonlocal noise thermometry [48]. They are also relevant for experimental interpretation of macroscopic transport measurements in graphene Hall bars.…”

Direct Determination of the Topological Thermal Conductance via Local Power Measurement

“…The first is the backscattering of plasmon modes at the edge-mode contact interface [S4, S7]. This term is length independent and proportional to the difference in temperatures squared, 𝑃 d→u 1 (𝑇 1 , 𝑇 2 , 𝑙) ∝ 𝑇 1 2 − 𝑇 2 2 . The exact coefficient depends on an exact theory of the edge modes.…”

“…), where 𝐼 is the impinging DC current, 𝑒 ⋆ the particles' charge and 𝜒(𝑥) = coth(𝑥) − 1 𝑥 . The excess power carried by the partitioned edge mode has two contributions: the trivial electrical power due to the transmitted direct current, 𝑃 DC = 1 2𝐺 2T (𝑡𝐼) 2 , and the power stored in current fluctuations at all frequencies,…”