Tunneling measurements of the zero-bias conductance peak and the Bi-Sr-Ca-Cu-O thin-film energy gap

Abstract

We have examined the zero-bias conductance peak that is often found in high-temperaturesuperconductor tunnel-junction spectra. We have also measured the Bi-Sr-Ca-Cu-O thin-film energy gap. The zero-bias conductance peak can be explained in terms of quasiparticle tunneling, phase diffusion, and a supercurrent. The implications of this model are discussed.

Andreev bound states in high temperature superconductors

“…Also for such junctions a zero bias conductance peak has been observed in most experiments [12,13,30,31,32,48]. Up to now the theoretically predicted zero bias conductance peak has been found for both SIN-and SIS-type junctions [25,49,50,51]. Below we present comprehensive experimental data on the tunneling conductance of various high temperature superconducting GBJs giving a very complete view of the zero bias conductance peak as a consequence of Andreev bound states.…”

“…Beyond the ABS scenario, the Appelbaum-Anderson model and the BlonderTinkham-Klapwijk model, phase diffusion in HTS Josephson junctions has been discussed [24,25]. However, any conductance peak related to a supercurrent should be restricted to a much smaller voltage scale than the mV-scale usually measured for the zero bias conductance peak in most experiments.…”

Influence of degraded surface layer of HTS on differential conductance of HTS/metal junctions

“…rhe((k,e) = exp(-iarccos(E/(k)) io(k)), (5) here z(k)1 is the direction-dependent modulus of the order parameter, and o(k) is its phase.…”

Angle-resolved photoemission as a probe ofα2Fin high-temperature superconductors: A study ofBi2Arnold1, Mueller2, Swihart3 1991Phys. Rev. Lett.47090View full textAdd to dashboardCite

“…This results in a ratio 2AQ/ksT c of 4.6 using the experimental T c -9l K or of 7.0 using our calculated T c =60 K. How does this compare with energy gaps of E^S^CaC^Os measured by other means? The low-temperature gap of this material has been measured by a variety of techniques including far-infrared reflectance [11] and transmission [12,13], tunneling [13][14][15], high-resolution electron-energy-loss spectroscopy [16], and photoemission [17,18]. Energy gaps A 0 from 0 to 34 meV have been reported by these techniques, so that our gap of 18 meV falls in this range.…”