Lee Sanghyun, Hashisaka Masayuki, Akiho Takafumi, Kobayashi Kensuke, Muraki Koji
NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan.
Graduate School of Science, Osaka University, 1-1, Machikaneyama, Toyonaka, Osaka 560-0043, Japan.
Rev Sci Instrum. 2021 Feb 1;92(2):023910. doi: 10.1063/5.0036419.
We show that a cryogenic amplifier composed of a homemade GaAs high-electron-mobility transistor (HEMT) is suitable for current-noise measurements in a mesoscopic device at dilution-refrigerator temperatures. The lower noise characteristics of our homemade HEMT lead to a lower noise floor in the experimental setup and enable more efficient current-noise measurement than is available with a commercial HEMT. We present the dc transport properties of the HEMT and the gain and noise characteristics of the amplifier. With the amplifier employed for current-noise measurements in a quantum point contact, we demonstrate the high resolution of the measurement setup by comparing it with that of the conventional one using a commercial HEMT.
我们表明，由自制的砷化镓高电子迁移率晶体管（HEMT）组成的低温放大器适用于在稀释制冷机温度下对介观器件进行电流噪声测量。我们自制的HEMT具有较低的噪声特性，这使得实验装置中的本底噪声更低，并且与商用HEMT相比，能够实现更高效的电流噪声测量。我们展示了HEMT的直流输运特性以及放大器的增益和噪声特性。通过将该放大器用于量子点接触中的电流噪声测量，我们将其与使用商用HEMT的传统测量装置进行比较，从而证明了该测量装置的高分辨率。
