Mitchell Institute for Fundamental Physics & Astronomy
College Station, Texas 77843
I will discuss the possibility of the odd frequency pairing, proposed initially by Berezinskii, in disordered conductors. In the first example, we considered the case of a very disordered system near an insulating state. There, an interplay of the Coulomb interaction with the strong disorder could be the source of the Cooper pairing in the triplet channel, which in turn may lead to the odd-frequency pairing. In the other considered case, such instability may develop in the vicinity of the transition into a superconducting state. I will discuss the existing experimental data in view of the considered exotic pairing. A hypothesis is put forward that the odd frequency pairing, unlike the even frequency pairing, leads to insulating behavior. Such an insulating state can be considered as an independent phase occurring before a regular superconducting transition.