Cornell researchers use voltage to switch graphene magnetism

Researchers at Cornell University have demonstrated a method to manipulate the magnetism of graphene using voltage, potentially influencing the development of future quantum materials. The study, published on October 14 in Nature Nanotechnology, explored a stack of four graphene layers. By applying voltage, the alignment of these layers was altered, switching the material between magnetic and nonmagnetic states. Notably, this change remained even after the voltage was removed.

Kenji Yasuda, an assistant professor in Cornell's School of Applied and Engineering Physics and the study's senior author, explained that the team leveraged the relatively weak interlayer bonds to modify the material's structure without disrupting the stronger intralayer bonds. In its typical stacking configuration, the four-layer graphene was nonmagnetic, but a different arrangement induced magnetism. The researchers successfully toggled the material between these states.

Daniel Brandon, the study's lead author and a doctoral student, noted that the persistent change in the material's state could be advantageous for memory applications. Although the technique holds promise for designing reconfigurable quantum materials, the researchers have not yet developed a commercial device. The research received primary support from the U.S. Department of Energy and utilized facilities at Cornell backed by the National Science Foundation.