Odd non-linear conductivity under spatial inversion in chiral Tellurium

TL;DR

This paper demonstrates that chiral Tellurium exhibits large, odd non-linear electrical conductivity dependent on crystal handedness, with potential applications in energy harvesting and wireless rectification.

Contribution

It provides the first experimental evidence that non-linear conductivity in chiral Tellurium is odd under spatial inversion and shows how electrostatic gating can significantly modulate this effect.

Findings

Non-linear conductivity in chiral Tellurium is odd under spatial inversion.

Electrostatic gating modulates non-linear response by a factor of 300.

Chiral Tellurium is suitable for energy-harvesting and rectification devices.

Abstract

Electrical transport in non-centrosymmetric materials departs from the well-established phenomenological Ohm's law. Instead of a linear relation between current and electric field, a non-linear conductivity emerges along specific crystallographic directions. This non-linear transport is fundamentally related to the lack of spatial inversion symmetry. However, the experimental implications of an inversion symmetry operation on the non-linear conductivity remain to be explored. Here, we report on a large, non-linear conductivity in chiral Tellurium. By measuring samples with opposite handedness, we demonstrate that the non-linear transport is odd under spatial inversion. Furthermore, by applying an electrostatic gate, we modulate the non-linear output by a factor of 300, reaching the highest reported value excluding engineered heterostructures. Our results establish chiral Te as an ideal compound not just to study the fundamental interplay between crystal structure, symmetry operations and non-linear transport, but also to develop wireless rectifiers and energy-harvesting chiral devices.