Ramp-edge junctions between superconducting Nd1.85Ce0.15CuO4 and La1.85Sr0.15CuO4

M. Hoek, F. Coneri, X. Wang, H. Hilgenkamp

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

We have fabricated in-plane ramp-edge junctions between Nd1.85Ce0.15CuO4 (NCCO) and La1.85Sr0.15CuO4 (LSCO) where both layers are superconducting. At the interface, we find an insulating barrier in electronic transport. The barrier is shown to be a tunneling barrier with a combination of inelastic and elastic tunneling, the former is indicated by the appearance of the LSCO phonon density of states in measurements and the latter is inferred from the temperature dependence of the conductance. The energy scale of the barrier is smaller than would be expected from band alignment found by considering the cuprates as degenerate semiconductors. It is closest to the scenario where hybridization of the O 2p valence band states dictate band alignment. Additional experiments with overdoped interlayers of Nd1.8Ce0.2CuO4 and La1.75Sr0.25CuO4 show that the origin of the barrier is most likely a combination of electronic depletion mainly in the NCCO and a strain effect in the LSCO.

Original languageEnglish
Article number035001
JournalSuperconductor science and technology
Volume29
Issue number3
DOIs
Publication statusPublished - 22 Jan 2016

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ramps
Valence bands
Semiconductor materials
alignment
electronics
Experiments
cuprates
interlayers
depletion
Temperature
valence
temperature dependence
energy

Keywords

  • boundary condition
  • particle creation and annihilation
  • quantum graphs
  • semiclassical methods
  • spectral functions

Cite this

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title = "Ramp-edge junctions between superconducting Nd1.85Ce0.15CuO4 and La1.85Sr0.15CuO4",
abstract = "We have fabricated in-plane ramp-edge junctions between Nd1.85Ce0.15CuO4 (NCCO) and La1.85Sr0.15CuO4 (LSCO) where both layers are superconducting. At the interface, we find an insulating barrier in electronic transport. The barrier is shown to be a tunneling barrier with a combination of inelastic and elastic tunneling, the former is indicated by the appearance of the LSCO phonon density of states in measurements and the latter is inferred from the temperature dependence of the conductance. The energy scale of the barrier is smaller than would be expected from band alignment found by considering the cuprates as degenerate semiconductors. It is closest to the scenario where hybridization of the O 2p valence band states dictate band alignment. Additional experiments with overdoped interlayers of Nd1.8Ce0.2CuO4 and La1.75Sr0.25CuO4 show that the origin of the barrier is most likely a combination of electronic depletion mainly in the NCCO and a strain effect in the LSCO.",
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language = "English",
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Ramp-edge junctions between superconducting Nd1.85Ce0.15CuO4 and La1.85Sr0.15CuO4. / Hoek, M.; Coneri, F.; Wang, X.; Hilgenkamp, H.

In: Superconductor science and technology, Vol. 29, No. 3, 035001, 22.01.2016.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - Ramp-edge junctions between superconducting Nd1.85Ce0.15CuO4 and La1.85Sr0.15CuO4

AU - Hoek, M.

AU - Coneri, F.

AU - Wang, X.

AU - Hilgenkamp, H.

PY - 2016/1/22

Y1 - 2016/1/22

N2 - We have fabricated in-plane ramp-edge junctions between Nd1.85Ce0.15CuO4 (NCCO) and La1.85Sr0.15CuO4 (LSCO) where both layers are superconducting. At the interface, we find an insulating barrier in electronic transport. The barrier is shown to be a tunneling barrier with a combination of inelastic and elastic tunneling, the former is indicated by the appearance of the LSCO phonon density of states in measurements and the latter is inferred from the temperature dependence of the conductance. The energy scale of the barrier is smaller than would be expected from band alignment found by considering the cuprates as degenerate semiconductors. It is closest to the scenario where hybridization of the O 2p valence band states dictate band alignment. Additional experiments with overdoped interlayers of Nd1.8Ce0.2CuO4 and La1.75Sr0.25CuO4 show that the origin of the barrier is most likely a combination of electronic depletion mainly in the NCCO and a strain effect in the LSCO.

AB - We have fabricated in-plane ramp-edge junctions between Nd1.85Ce0.15CuO4 (NCCO) and La1.85Sr0.15CuO4 (LSCO) where both layers are superconducting. At the interface, we find an insulating barrier in electronic transport. The barrier is shown to be a tunneling barrier with a combination of inelastic and elastic tunneling, the former is indicated by the appearance of the LSCO phonon density of states in measurements and the latter is inferred from the temperature dependence of the conductance. The energy scale of the barrier is smaller than would be expected from band alignment found by considering the cuprates as degenerate semiconductors. It is closest to the scenario where hybridization of the O 2p valence band states dictate band alignment. Additional experiments with overdoped interlayers of Nd1.8Ce0.2CuO4 and La1.75Sr0.25CuO4 show that the origin of the barrier is most likely a combination of electronic depletion mainly in the NCCO and a strain effect in the LSCO.

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