Projekteja vuodessa
Abstrakti
The evidence for proximity-induced superconductivity in heterostructures of topological insulators and high-Tc cuprates has been intensely debated. We use molecular-beam epitaxy to grow thin films of topological insulator Bi2Te3 on a cuprate Bi2Sr2CaCu2O8+x, and study the surface of Bi2Te3 using low-temperature scanning tunneling microscopy and spectroscopy. In few unit-cell thick Bi2Te3 films, we find a V-shaped gap-like feature at the Fermi energy in dI/dV spectra. By reducing the coverage of Bi2Te3 films to create nanoscale islands, we discover that this spectral feature dramatically evolves into a much larger hard gap, which can be understood as a Coulomb blockade gap. This conclusion is supported by the evolution of dI/dV spectra with the lateral size of Bi2Te3 islands, as well as by topographic measurements that show an additional barrier separating Bi2Te3 and Bi2Sr2CaCu2O8+x. We conclude that the prominent gap-like feature in dI/dV spectra in Bi2Te3 films is not a proximity-induced superconducting gap. Instead, it can be explained by Coulomb blockade effects, which take into account additional resistive and capacitive coupling at the interface. Our experiments provide a fresh insight into the tunneling measurements of complex heterostructures with buried interfaces.
Alkuperäiskieli | Englanti |
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Artikkeli | 72 |
Julkaisu | npj Quantum Materials |
Vuosikerta | 5 |
Numero | 1 |
DOI - pysyväislinkit | |
Tila | Julkaistu - 14 lokak. 2020 |
OKM-julkaisutyyppi | A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä |
Sormenjälki
Sukella tutkimusaiheisiin 'Coulomb blockade effects in a topological insulator grown on a high-T c cuprate superconductor'. Ne muodostavat yhdessä ainutlaatuisen sormenjäljen.Projektit
- 2 Päättynyt
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Kvanttiteknologian huippuyksikkö
Flindt, C. (Vastuullinen tutkija), Potanina, E. (Projektin jäsen), Burset Atienza, P. (Projektin jäsen) & Pyhäranta, T. (Projektin jäsen)
01/01/2018 → 31/12/2020
Projekti: Academy of Finland: Other research funding
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Kvantmekanisk styrning av elektrisk laddning, värme och entropi produktion i nanokomponenter
Flindt, C. (Vastuullinen tutkija), Deger, A. (Projektin jäsen), Potanina, E. (Projektin jäsen), Norrman Brange, F. (Projektin jäsen), Roussel, B. (Projektin jäsen), Vecsei, P. (Projektin jäsen), Menczel, P. (Projektin jäsen) & Pyhäranta, T. (Projektin jäsen)
01/09/2017 → 31/12/2021
Projekti: Academy of Finland: Other research funding