Phase-change memory function of correlated electrons in organic conductors

TL;DR

This paper demonstrates phase-change memory functions based on charge configuration states in organic conductors, showing reversible switching between charge-ordered and charge-glass states with potential for fast, non-volatile memory applications.

Contribution

It introduces a novel PCM mechanism utilizing charge configurations in correlated electron systems, expanding the scope of memory materials beyond traditional phase-change materials.

Findings

Reversible switching between charge-ordered and charge-glass states achieved.

Faster switching observed in materials with higher critical cooling rates.

Material cooling rate influences switching speed and stability.

Abstract

Phase-change memory (PCM), a promising candidate for next-generation non-volatile memories, exploits quenched glassy and thermodynamically stable crystalline states as reversibly switchable state variables. We demonstrate PCM functions emerging from a charge-configuration degree of freedom in strongly correlated electron systems. Non-volatile reversible switching between a high-resistivity charge-crystalline (or charge-ordered) state and a low-resistivity quenched state, charge glass, is achieved experimentally via heat pulses supplied by optical or electrical means in organic conductors $\theta$-(BEDT-TTF)$_2$$X$. Switching that is one order of magnitude faster is observed in another isostructural material that requires faster cooling to kinetically avoid charge crystallization, indicating that the material's critical cooling rate can be useful guidelines for pursuing a faster correlated-electron PCM function.