Thanks to an international collaboration around one of our own home-made microscopes, researchers at IFIMAC have observed quantized states at the surface of the superconducting heavy fermion compound URu2Si2. The work shows that two-dimensional surface heavy fermions are scattered at steps, forming a quantization pattern from which an electron effective mass as high as 17 times the free electron mass is extracted. The connection between the two-dimensional heavy fermions and bulk superconductivity has been established thanks to the collaborative work of IFIMAC theoreticians and experimentalists.
One consequence of the heavy mass is an extremely small separation between quantized levels, about three orders of magnitude below quantization in usual metals. IFIMAC researchers will now search for such quantized levels in other materials. The list is long and includes heavy fermion materials showing almost invariably exotic and exciting phenomena, such as highly unconventional triplet superconductors or magnetic quantum critical fluctuations. [Full article]
