论文标题
高带宽，可变抗差噪声温度计
High-Bandwidth, Variable-Resistance Differential Noise Thermometry
论文作者
论文摘要
我们开发了适用于具有可变源阻抗的可变源阻抗的Johnson噪声温度，可用于快速数据采集。通过实现差异噪声测量和两阶段阻抗匹配，我们在频率范围内证明了噪声测量值120-250 MHz，其样品电阻范围为30Ω-100kΩ，通过门电压和温度调节。我们采用高频，单端的低噪声放大器，该放大器保持在恒定的低温温度下，以保持所需的低噪声温度。我们在10 K背景下以30 s平均的温度精度达到温度计校准，最高650 mk。使用这种差分噪声温度测定技术，我们测量了在宽的电阻范围内跨越金属和半导体方案的双层石墨烯样品上的导热率，并将其与电导率进行比较。
We develop Johnson noise thermometry applicable to mesoscopic devices with variable source impedance with high bandwidth for fast data acquisition. By implementing differential noise measurement and two-stage impedance matching, we demonstrate noise measurement in the frequency range 120-250 MHz with a wide sample resistance range 30 Ω-100 kΩ tuned by gate voltages and temperature. We employ high-frequency, single-ended low noise amplifiers maintained at a constant cryogenic temperature in order to maintain the desired low noise temperature. We achieve thermometer calibration with temperature precision up to 650 mK on a 10 K background with 30 s of averaging. Using this differential noise thermometry technique, we measure thermal conductivity on a bilayer graphene sample spanning the metallic and semiconducting regimes in a wide resistance range, and we compare it to the electrical conductivity.
