Nonequilibrium noise measurements using hBN tunnel barriers

Xuanhan Zhao¹, Loah A. Stevens¹, Panpan Zhou¹, K. Watanabe², T. Taniguchi², Douglas Natelson<sup>1,3,4

1</sup>Department of Physics and Astronomy, Rice University, Houston, TX 77005
²National Institute for Materials Science, Tsukuba, Japan 305-0047
³Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005
⁴Department of Materials Science and NanoEngineering, Rice University, Houston, TX 77005

Nonequilibrium (or “shot”) noise, which comprises the inherent fluctuations in the electrical current of system driven out of equilibrium, is predicted to be an outstanding experimental probe for underlying physics in many systems. Hexagonal boron nitride is a 2D material with atomically smooth surface available down to thicknesses of single atomic layers and possessing a large bandgap，which makes it an ideal choice for fabrication of tunnel junction. Here we report nonequilibrium charge current noise measurements in a variety of tunnel junctions prepared using different ways of transferring hBN as monolayer tunnel barriers. We will further discuss the prospect of making single-layer hBN a general tool for tunneling spectroscopy of materials.