Scientists at Rice University have discovered that tiny wrinkles in atomically thin materials can control electron spin—a breakthrough that could pave the way for ultra-compact, energy-efficient spintronic devices. Instead of relying on electron charge, which powers conventional silicon computing, this approach leverages the quantum property of spin, toggling between up and down states, to process data more efficiently.
Traditional devices face a major hurdle: electron spin information tends to decay quickly due to scattering and collisions. The Rice team found that bending 2D materials like molybdenum ditelluride induces a unique spin texture known as a persistent spin helix (PSH). In simple terms, while electrons in standard materials change their spin when they change direction, the PSH state keeps the electron spin steady, even in a disruptive environment.
How does it work? When a 2D material wrinkles, its top layer stretches and the bottom layer compresses, shifting electrical charges and creating an internal electric field—a process called flexoelectric polarization. This effect splits the energy bands of spin-up and spin-down electrons, and with increased curvature, sets up a helix-like structure that flips between states over just one nanometre. This mechanism not only preserves spin but also opens the door to significantly smaller device designs.
If you’ve ever played with bending a thin sheet of paper, you might appreciate the beauty of how natural undulations create distinct patterns. Here, common wrinkles and hairpin-like loops in the material become the key to stabilising electron spin. Sunny Gupta, a Rice alumnus and co-author of the study, explains it neatly: while typical materials see electrons alter their spin with shifts in momentum, these specially engineered wrinkles maintain a fixed spin state.
This innovative research combines quantum physics with elastic mechanics—two fields that rarely intersect—to overcome a longstanding limitation in spintronics. Supported by agencies such as the U.S. Office of Naval Research, the Army Research Office, the National Science Foundation, the Department of Energy, and the Department of Defense, the findings, published in Matter, suggest that spin-based technology could eventually lead to devices that are not only more energy-efficient but also more compact than ever before.
