Schaefer Brian T, Wang Lei, Jarjour Alexander, Watanabe Kenji, Taniguchi Takashi, McEuen Paul L, Nowack Katja C
Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY, 14853, USA.
Kavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca, NY, 14853, USA.
Nat Commun. 2020 Aug 20;11(1):4163. doi: 10.1038/s41467-020-18007-5.
Solid-state magnetic field sensors are important for applications in commercial electronics and fundamental materials research. Most magnetic field sensors function in a limited range of temperature and magnetic field, but Hall sensors in principle operate over a broad range of these conditions. Here, we evaluate ultraclean graphene as a material platform for high-performance Hall sensors. We fabricate micrometer-scale devices from graphene encapsulated with hexagonal boron nitride and few-layer graphite. We optimize the magnetic field detection limit under different conditions. At 1 kHz for a 1 μm device, we estimate a detection limit of 700 nT Hz at room temperature, 80 nT Hz at 4.2 K, and 3 μT Hz in 3 T background field at 4.2 K. Our devices perform similarly to the best Hall sensors reported in the literature at room temperature, outperform other Hall sensors at 4.2 K, and demonstrate high performance in a few-Tesla magnetic field at which the sensors exhibit the quantum Hall effect.
固态磁场传感器对于商业电子产品应用和基础材料研究而言至关重要。大多数磁场传感器在有限的温度和磁场范围内发挥作用，但霍尔传感器原则上可在这些条件的广泛范围内运行。在此，我们评估超洁净石墨烯作为高性能霍尔传感器的材料平台。我们用六方氮化硼和少层石墨封装的石墨烯制造微米级器件。我们在不同条件下优化磁场检测极限。对于一个1μm的器件，在1kHz时，我们估计室温下的检测极限为700nT/Hz，4.2K时为80nT/Hz，在4.2K的3T背景磁场中为3μT/Hz。我们的器件在室温下的性能与文献中报道的最佳霍尔传感器相似，在4.2K时优于其他霍尔传感器，并在几特斯拉的磁场中表现出高性能，此时传感器呈现量子霍尔效应。
