superconductors

The transition temperature (T_C) between normal and superconducting states usually exhibits a dramatic increase or decrease with increasing applied pressure. Here we present, in contrast, a new kind of superconductor that exhibits the exotic feature that T_C is robust against large volume shrinkages induced by applied pressure (here naming them as “RSAVS superconductors”). This RSAVS behavior, which has never been predicted or proposed as a new kind of superconductors previously, occurs universally in a certain kind of superconductors with body centered cubic lattice. Our electronic structure calculations indicate that in the RSAVS state the contribution of the degenerate dx²-y² and dz² orbital electrons remains almost unchanged at the Fermi level, suggesting that these are the electrons that may play a crucial role in stabilizing the T_C in the RSAVS state. We preliminarily analyzed the reasonability and validity of this suggestion by the Homes’ law.