On the possibility of new high T c superconductors by producing metal heterostructures as in the cuprate perovskites

Abstract

Here we propose a possible way to produce superconductors with high critical temperature T c by confinement of a Fermi liquid in a superlattice of quantum stripes (wells, wires or dots). The enhancement of T c is obtained by tuning the size L of the stripes (wells, wires or dots), and the wavelength of electrons at the Fermi level λ F at the resonance condition L∼λ F. The 3D superconducting phase is stabilized by the condition that the separation W between the stripes (wells, wires or dots) should be of the order of the coherence length ξ 0. This quantum state is realized in Bi 2Sr 2Ca 2Cu 2O 8+y superconductor with T c =84 K, where the resonance condition k Fy∼π/ L for the component of the Fermi wavevector normal to the stripe direction holds. This work gives the parameters for the design of new superconducting materials with higher T c made of metal heterostructures approaching the atomic limit.