Picosecond electric-field-induced threshold switching in phase-change materials

TL;DR

This paper demonstrates that threshold switching in phase-change materials can occur within sub-picosecond electric pulses, supporting electronic models and enabling ultrafast switching applications.

Contribution

It provides experimental evidence that threshold switching can happen on sub-picosecond timescales, favoring electronic over nucleation models.

Findings

Threshold switching occurs within sub-picosecond electric pulses.

Reversible conductivity changes are observed under electric field.

Potential for ultrafast electronic switching applications.

Abstract

Many chalcogenide glasses undergo a breakdown in electronic resistance above a critical field strength. Known as threshold switching, this mechanism enables field-induced crystallization in emerging phase-change memory. Purely electronic as well as crystal nucleation assisted models have been employed to explain the electronic breakdown. Here, picosecond electric pulses are used to excite amorphous Ag$_4$In$_3$Sb$_{67}$Te$_{26}$. Field-dependent reversible changes in conductivity and pulse-driven crystallization are observed. The present results show that threshold switching can take place within the electric pulse on sub-picosecond time-scales - faster than crystals can nucleate. This supports purely electronic models of threshold switching and reveals potential applications as an ultrafast electronic switch.