The amplification of the superconducting critical temperature Tc from the low temperature range in homogeneous 2D planes (Tc < 23 K) to the high temperature range (23K < Tc < 150K) in an artificial heterostructure of quantum stripes is calculated. The high Tc is obtained by tuning the chemical potential μ near the bottom of the nth subband (En), at a “shape resonance”, in a range μ-En ∼ ωD, where ωD is the energy cutoff for the pairing interaction. The resonance for the gap Δn at the nth “shape resonance” is studied for a free electron gas in the BCS approximation imation as a function of the stripe width L, and of the number of electrons ϱ per unit surface. An amplification factor 650>Gap_3/Gap_inf>6 for coupling 0.1 < λ < 0.3 is obtained at the third shape resonance raising the critical temperature in the high Tc range.
The gap amplification at a shape resonance in a superlattice of quantum stripes: A mechanism for high Tc
PERALI, Andrea;
1996-01-01
Abstract
The amplification of the superconducting critical temperature Tc from the low temperature range in homogeneous 2D planes (Tc < 23 K) to the high temperature range (23K < Tc < 150K) in an artificial heterostructure of quantum stripes is calculated. The high Tc is obtained by tuning the chemical potential μ near the bottom of the nth subband (En), at a “shape resonance”, in a range μ-En ∼ ωD, where ωD is the energy cutoff for the pairing interaction. The resonance for the gap Δn at the nth “shape resonance” is studied for a free electron gas in the BCS approximation imation as a function of the stripe width L, and of the number of electrons ϱ per unit surface. An amplification factor 650>Gap_3/Gap_inf>6 for coupling 0.1 < λ < 0.3 is obtained at the third shape resonance raising the critical temperature in the high Tc range.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
