Reproducible, scalable in situ manufacturing method for quantum moiré interfaces

Stanford researcher Professor Fang Liu and her student, Greg Zaborski Jr., have developed a more uniform, reproducible, efficient fabrication method for moiré structures in 2d materials that produces structures with cleaner interfaces, near perfect yield, and mass production compatible sizing (centimeter size vs current micron size).

Created via precise stacking or 'relative twist' of van der Waals (vdW) layers, moiré superlattices exhibit unpredicted and unexpected emergent electronics states, including superconductivity, making them attractive for a wide range of applications such as quantum devices, sensors, superconductors, ferroelectric memory, spintronic devices, and metamaterials. The most common preparation method (tear-and-stack of Scotch tape exfoliated monolayers) is inefficient, unreproducible, and suffers twist angle inhomogeneity, interfacial contamination, micrometer sizes, and a tendency to untwist at elevated temperatures.

The Fang Liu Group fabrication method (see Figure 1) produces moiré superlattices from a wide range of 2D materials with unprecedented uniformity and versatility, achieving much higher throughput and near-unity yield over centimeter-scale macroscopic areas, representing a significant improvement compared to conventional techniques. The target twist angle in homo twisted moiré structures can be precisely controlled (either manually or through automated processes), due to the perfect lattice alignment of the exfoliated monolayer within the original van der Waals layered crystal. Furthermore, the macroscopic dimension enhances thermal stability of the small twist angle structures, preventing untwisting under high-temperature processes that are essential for device fabrications.

Stage of development - Prototype