Universal Scaling and Signatures of Nodal Structures in Electron Tunneling from Two-Dimensional Semimetals
Year: 2020
Type: preprint
Abstract: We present the theory of out-of-plane electron thermal-field emission from 2D semimetals. We show that the current($\mathcal{J}$)-field($F$)-temperature($T$) characteristic is captured by a universal scaling law applicable for broad classes of 2D semimetals, including monolayer and few-layer graphene, nodal point semimetals, nodal line semimetals and Dirac semimetals at the verge of topological phase transition. The low-temperature scaling takes the universal form, $\log\left( \mathcal{J}/F^\gamma \right) \propto -1/F$ with $\gamma = 1$ for 2D semimetals, which is in stark contrast to the classic Fowler-Nordheim scaling of $\gamma = 2$ for 3D metals. Importantly, the Fermi level dependence of the tunneling currents depends sensitively on the nodal structure through the electronic density of states, thus serving as a probe for detecting the various possible nodal structures of 2D semimetals. Our findings provide a theoretical basis for the understanding of tunneling charge transport phenomena in solid/vacuum and solid/solid interfaces, critical for the development of 2D-material-based vacuum and solid-state electronic devices.
Source: arXiv (Cornell University)
Authors: Yee Sin Ang, Ching Hua Lee, L. K. Ang
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W3014154743