University of Washington researchers tune graphene resistance with strain

New variable for moiré materials

Scientists previously used temperature, voltage and magnetic fields to alter the properties of twisted carbon sheets. Now a team led by Matthew Yankowitz has introduced mechanical strain as a new control method. The group published their findings in the journal Science on November 12. This approach allows them to manipulate the atomic lattice directly without relying solely on external fields.

Collaboration with Jiun-Haw Chu

The project involved close collaboration between Yankowitz and physics professor Jiun-Haw Chu at the University of Washington. Their work addresses the difficulty of placing microscopic atom sheets perfectly flat without creating wrinkles or distortions. When these layers twist to 1.1 degrees, they form a complex moiré pattern that can become superconducting near absolute zero. Adding strain creates big swings in how easily electrons flow through this specific material structure.

Tool for quantum devices

Senior author Matthew Yankowitz stated that deforming the lattice enables experiments previously impossible to conduct. This technique helps researchers cycle through different states of matter within a single sample device. The ability to switch between metals, insulators and superconductors in one unit simplifies testing exotic quantum states. These results provide an additional tool for probing mysterious materials in labs around the world.