THE GAP AMPLIFICATION AT A SHAPE RESONANCE IN A SUPERLATTICE OF QUANTUM STRIPES - A MECHANISM FOR HIGH T-C

The amplification of the superconducting critical temperature T-c from the low temperature range in homogeneous 2D planes (T-c < 23 K) to th e high temperature range (23 K < T-c < 150 K) in an artificial heteros tructure of quantum stripes is calculated. The high T-c is obtained by tuning the chemical potential mu near the bottom of the nth subband ( E(n)), at a ''shape resonance'', in a range mu-E(n) similar to HBAR om ega(D), where HBAR omega(D) is the energy cutoff for the pairing inter action. The resonance for the gap Delta(n) at the nth ''shape resonanc e'' is studied for a free electron gas in the BCS approximation as a f unction of the stripe width L, and of the number of electrons rho per unit surface. An amplification factor 650 > Delta(3)/Delta(infinity) > 6 for coupling 0.1 < lambda < 0.3 is obtained at the third shape reso nance raising the critical temperature in the high T-c range. Copyrigh t (C) 1996 Elsevier Science Ltd