Cumings’ Research on Paramagnetic Semiconductors Published in Physical Review LettersMaterials Science and Engineering professor John Cumings, in collaboration with colleagues at Stanford University, Penn State University, and the National High Magnetic Field Laboratory (Los Alamos, New Mexico), has published groundbreaking research on the discovery of a previously unknown magnetic property of a nonferromagnetic alloy of zinc, cadmium, manganese, and selenium. The paper, titled "Tunable Anomalous Hall Effect in a Nonferromagnetic System," appears in Physical Review Letters 96, 196404 (2006). Cumings and his colleagues also presented the paper at Harvard University, Michigan State University, Rice University, Hitachi (Almaden facility, San Jose) and the Kavli Institute (Santa Barbara) during the spring semester of 2006.
Unlike ferromagnetic materials whose spin (magnetic strength) is predetermined by their chemical makeup, the properties of paramagnetic semiconductors like the alloy in Cumings’ study can be tuned by varying carrier density, magnetic field, or temperature. The ability to control the spin of and electron transport through a material makes it flexible; it can be used in multiple applications and devices, and its magnetic properties can be altered or turned on and off as needed. Devices created with such materials—spintronics—could prove to be more efficient and diversified than traditional electronics.
Published June 13, 2006