Shedding light on new type of magnetism in quantum materials

Researchers at Rice University have identified a new form of magnetism known as altermagnetism in ruthenium dioxide. While bulk ruthenium dioxide shows no magnetic properties, the team discovered that when the material is prepared as an ultrathin film, it exhibits unconventional magnetic behavior. This discovery challenges previous assumptions about the material and offers a new pathway for advanced computing hardware.

Ming Yi, an associate professor of physics and astronomy at Rice, led the study alongside collaborators from the University of Minnesota and the Paul Scherrer Institute. The team used a technique called spin-resolved angle-resolved photoemission spectroscopy to observe the spin texture of the material. By measuring how electron spins arrange themselves in space, the researchers confirmed the existence of this unique magnetic state.

A critical factor in producing this effect is lattice strain. When the material is placed under pressure, the electron structure changes in a way that allows altermagnetism to emerge. Without this specific strain, the material remains non-magnetic. This dependency acts as a physical tuning knob, which may allow engineers to control magnetism in future devices.

This finding holds significant implications for the future of spintronics and RAM architecture. By demonstrating that material properties change drastically between bulk and ultrathin states, the researchers have provided a new method for material design. Their work highlights the necessity of precise material preparation and measurement protocols when studying quantum materials. The study was supported by the U.S. Department of Energy and several private foundations.