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Title: Development of high frequency and wide bandwidth Johnson noise thermometry

We develop a high frequency, wide bandwidth radiometer operating at room temperature, which augments the traditional technique of Johnson noise thermometry for nanoscale thermal transport studies. Employing low noise amplifiers and an analog multiplier operating at 2 GHz, auto- and cross-correlated Johnson noise measurements are performed in the temperature range of 3 to 300 K, achieving a sensitivity of 5.5 mK (110 ppm) in 1 s of integration time. This setup allows us to measure the thermal conductance of a boron nitride encapsulated monolayer graphene device over a wide temperature range. Our data show a high power law (T ∼ 4) deviation from the Wiedemann-Franz law above T ∼ 100 K.
Authors:
; ;  [1] ; ;  [2]
  1. Department of Physics, Harvard University, Cambridge, Massachusetts 02138 (United States)
  2. Quantum Information Processing Group, Raytheon BBN Technologies, Cambridge, Massachusetts 02138 (United States)
Publication Date:
OSTI Identifier:
22399133
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 106; Journal Issue: 2; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; AMPLIFIERS; BORON NITRIDES; GHZ RANGE; GRAPHENE; NANOSTRUCTURES; NOISE; RADIOMETERS; SENSITIVITY; TEMPERATURE DEPENDENCE; TEMPERATURE RANGE 0273-0400 K; THERMAL CONDUCTION; THERMAL CONDUCTIVITY; WIEDEMANN-FRANZ LAW