Observation of Two-Dimensional Bulk Electronic States in a Superconducting Topological Insulator Heterostructure Cux(PbSe)5(Bi2Se3)6: Implications for Unconventional Superconductivity

Abstract

We have performed angle-resolved photoemission spectroscopy (ARPES) on Cux(PbSe)5(Bi2Se3)6 (CPSBS; x = 1.47), a superconductor derived from a topological insulator heterostructure, to elucidate the electronic states relevant to the occurrence of possible unconventional superconductivity. Upon Cu intercalation into the parent compound (PbSe)5(Bi2Se3)6, we observed a distinct energy shift of the bulk conduction band due to electron doping. Photon-energy dependent ARPES measurements of CPSBS revealed that the observed bulk band forms a cylindrical electronlike Fermi surface at the Brillouin-zone center. The two-dimensional nature of the bulk electronic states suggests the occurrence of odd-parity Eu pairing or even-parity d-wave pairing, both of which may provide a platform of Majorana bound states in the superconducting state.

5 pages, 3 figures

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Cited by in corpus (8)

• Nematic superconductivity in doped Bi2Se3 topological superconductors
• Superconductivity in doped Dirac semimetals
• Exploring Topological Superconductivity in Topological Materials
• Generalized Anderson's theorem for superconductors derived from topological insulators
• Nematic Superconductivity in Cu1.5(PbSe)5(Bi2Se3)6
• Nano-mosaic of Topological Dirac States on the Surface of Pb5Bi24Se41 Observed by Nano-ARPES
• Fermiology of possible topological superconductor Tl0.5Bi2Te3 derived from hole-doped topological insulator
• Quasiparticle interference on the surface of Bi${}_2$Se${}_3$ terminated (PbSe)${}_5$(Bi${}_2$Se${}_3$)${}_6$