Ultrathin Bismuth Film on High-Temperature Cuprate Superconductor Bi2Sr2CaCu2O8+δ as a Candidate of a Topological Superconductor

Natsumi Shimamura, Katsuaki Sugawara, Sukrit Sucharitakul, Seigo Souma, Katsuya Iwaya, Kosuke Nakayama, Chi Xuan Trang, Kunihiko Yamauchi, Tamio Oguchi, Kazutaka Kudo, Takashi Noji, Yoji Koike, Takashi Takahashi, Tetsuo Hanaguri, Takafumi Sato

Research output: Contribution to journalArticle

Abstract

One of the key challenges in condensed-matter physics is to establish a topological superconductor that hosts exotic Majorana fermions. Although various heterostructures consisting of conventional BCS (Bardeen-Cooper-Schrieffer) superconductors as well as doped topological insulators were intensively investigated, no conclusive evidence for Majorana fermions has been provided. This is mainly because of their very low superconducting transition temperatures (Tc) and small superconducting-gap magnitude. Here, we report a possible realization of topological superconductivity at very high temperatures in a hybrid of Bi(110) ultrathin film and copper oxide superconductor Bi2Sr2CaCu2O8+δ (Bi2212). Using angle-resolved photoemission spectroscopy and scanning tunneling microscopy, we found that three-bilayer-thick Bi(110) on Bi2212 exhibits a proximity-effect-induced s-wave energy gap as large as 7.5 meV which persists up to Tc of Bi2212 (85 K). The small Fermi energy and strong spin-orbit coupling of Bi(110), together with the large pairing gap and high Tc, make this system a prime candidate for exploring stable Majorana fermions at very high temperatures.

Original languageEnglish
JournalACS Nano
DOIs
Publication statusAccepted/In press - Jan 1 2018

Fingerprint

Bismuth
Fermions
bismuth
cuprates
Superconducting materials
fermions
Condensed matter physics
Oxide superconductors
condensed matter physics
Copper oxides
Ultrathin films
Scanning tunneling microscopy
copper oxides
Photoelectron spectroscopy
Superconductivity
Fermi level
Temperature
Superconducting transition temperature
oxide films
Heterojunctions

Keywords

  • electronic structure
  • high-temperature superconductor
  • proximity effect
  • spin-orbit coupling
  • topology
  • ultrathin film

ASJC Scopus subject areas

  • Materials Science(all)
  • Engineering(all)
  • Physics and Astronomy(all)

Cite this

Shimamura, N., Sugawara, K., Sucharitakul, S., Souma, S., Iwaya, K., Nakayama, K., ... Sato, T. (Accepted/In press). Ultrathin Bismuth Film on High-Temperature Cuprate Superconductor Bi2Sr2CaCu2O8+δ as a Candidate of a Topological Superconductor. ACS Nano. https://doi.org/10.1021/acsnano.8b04869

Ultrathin Bismuth Film on High-Temperature Cuprate Superconductor Bi2Sr2CaCu2O8+δ as a Candidate of a Topological Superconductor. / Shimamura, Natsumi; Sugawara, Katsuaki; Sucharitakul, Sukrit; Souma, Seigo; Iwaya, Katsuya; Nakayama, Kosuke; Trang, Chi Xuan; Yamauchi, Kunihiko; Oguchi, Tamio; Kudo, Kazutaka; Noji, Takashi; Koike, Yoji; Takahashi, Takashi; Hanaguri, Tetsuo; Sato, Takafumi.

In: ACS Nano, 01.01.2018.

Research output: Contribution to journalArticle

Shimamura, N, Sugawara, K, Sucharitakul, S, Souma, S, Iwaya, K, Nakayama, K, Trang, CX, Yamauchi, K, Oguchi, T, Kudo, K, Noji, T, Koike, Y, Takahashi, T, Hanaguri, T & Sato, T 2018, 'Ultrathin Bismuth Film on High-Temperature Cuprate Superconductor Bi2Sr2CaCu2O8+δ as a Candidate of a Topological Superconductor', ACS Nano. https://doi.org/10.1021/acsnano.8b04869
Shimamura, Natsumi ; Sugawara, Katsuaki ; Sucharitakul, Sukrit ; Souma, Seigo ; Iwaya, Katsuya ; Nakayama, Kosuke ; Trang, Chi Xuan ; Yamauchi, Kunihiko ; Oguchi, Tamio ; Kudo, Kazutaka ; Noji, Takashi ; Koike, Yoji ; Takahashi, Takashi ; Hanaguri, Tetsuo ; Sato, Takafumi. / Ultrathin Bismuth Film on High-Temperature Cuprate Superconductor Bi2Sr2CaCu2O8+δ as a Candidate of a Topological Superconductor. In: ACS Nano. 2018.
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