Artificial event horizons in Weyl semimetal heterostructures and their non-equilibrium signatures

TL;DR

This paper explores how Weyl semimetal heterostructures can mimic black-hole horizons, revealing non-equilibrium signatures like conductance peaks that could be experimentally observed.

Contribution

It provides an exact scattering solution for Weyl heterostructures with horizons and shows how non-equilibrium conditions enhance Hawking-like radiation signatures.

Findings

Exact scattering solution for Weyl heterostructures

Non-equilibrium states amplify Hawking-like channels

Conductance peaks indicate artificial event horizons

Abstract

We investigate transport in type-I/type-II Weyl semi\-metal heterostructures that realize effective black- or white-hole event horizons. We provide an exact solution to the scattering problem at normal incidence and low energies, both for a sharp and a slowly-varying Weyl cone tilt profile. In the latter case, we find two channels with transmission amplitudes analog to those of Hawking radiation. Whereas the Hawking-like signatures of these two channels cancel in equilibrium, we demonstrate that one can favor the contribution of either channel using a non-equilibrium state, either by irradiating the type-II region or by coupling it to a magnetic lead. This in turn gives rise to a peak in the two-terminal differential conductance which can serve as an experimental indicator of the artificial event horizon.