Superconducting cuprate heterostructures for hot electron bolometers

摘要

Transport properties of the resistive state of quasi-two dimensional superconducting heterostructures containing ultrathin La_(2-x)Sr_xCuO_4 layers synthesized using molecular beam epitaxy are studied. The electron transport exhibits strong deviation from Ohm's law, δV ～ γI~3, with a coefficient γ(T) that correlates with the temperature variation of the resistivity dρ/dT. Close to the normal state, analysis of the nonlinear behavior in terms of electron heating yields an electron-phonon thermal conductance per unit area g_(e-ph) ≈ 1 W/Kcm~2 at T = 20K, one-two orders of magnitude smaller than in typical superconductors. This makes superconducting LaSrCuO heterostructures to be attractive candidate for the next generation of hot electron bolometers with greatly improved sensitivity.