The pathway to chirality in elemental tellurium

TL;DR

This paper uses advanced simulations to uncover how elemental tellurium forms chiral crystal structures, revealing transient structures that enable rapid crystallization and chirality transfer, which explains device switching behavior.

Contribution

It provides the first detailed microscopic understanding of the mechanisms behind chirality formation in elemental tellurium through quantum-mechanical simulations.

Findings

Identification of a transient cube-like structural motif in Te crystallization

Explanation of rapid crystallization process in elemental Te

Insight into chirality transfer mechanisms affecting device behavior

Abstract

Chiral crystals, like chiral molecules, cannot be superimposed onto their mirror images -- a fundamental property that has been linked to interesting physical behavior and exploited in functional devices. Among the simplest inorganic systems with crystallographic chirality, elemental tellurium adopts crystal structures with right- or left-handed chains. However, understanding the formation mechanisms of those structures has been difficult due to the rapid crystallization of Te, which reaches the spatial and temporal resolution limits of even the most advanced experiments. Here, we report ultra-large-scale, quantum-mechanically accurate simulations that reveal mechanisms of crystallization and the origin of crystallographic chirality in solid Te. We identify a characteristic, disordered cube-like structural motif -- a transient bonding environment with only nanosecond lifetime -- that enables both the rapid crystallization of Te and mediates chirality transfer. Based on the resulting microscopic understanding, we are able to explain the switching behavior of Te-based electrical devices.