A copper oxide's electronic structure

Abstract

Physics![Figure][1] Superconducting copper-oxide electronic structurePHOTO: NICOLLE R. FULLER Physicists still do not understand why some copper-oxide compounds become superconducting at relatively high temperatures. Even more basic issues have remained controversial as well, such as the electronic structure of the normal (i.e., nonsuperconducting) state from which superconductivity emerges. Sebastian et al. chose YBa2Cu3O6.56 as a good representative of a subclass of these compounds and used high magnetic fields to suppress its superconductivity and reach its normal state. They analyzed the wiggles of the electrical resistivity to map out the shape of the so-called Fermi surface, which separates the quantum states filled with electrons from the empty ones. They found an undulating shape that suggested that the electronic structure was organized differently from what one expects based on the crystal lattice structure alone. Nature 10.1038/nature13326 (2014). [1]: pending:yes