Quantized Nonlinear Conductance in Ballistic Metals

We introduce a nonlinear frequency-dependent D +1 terminal conductance that characterizes a D-dimensional Fermi gas, generalizing the Landauer conductance in D = 1. For a 2D ballistic conductor, we show that this conductance is quantized and probes the Euler characteristic of the Fermi sea. We critically address the roles of electrical contacts and Fermi liquid interactions, and we propose experiments on 2D Dirac materials, such as graphene, using a triple point contact geometry.

Automated summary

We introduce a nonlinear frequency-dependent D +1 terminal conductance that characterizes a D-dimensional Fermi gas, generalizing the Landauer conductance in D = 1. We show that for a 2D ballistic conductor, this conductance is quantized and can probe the Euler characteristic of the Fermi sea. We also critically analyze the roles of electrical contacts and Fermi liquid interactions, and propose experiments on 2D Dirac materials, such as graphene, using a triple point contact geometry.