The topology of the Fermi surface of Bi2212 from angle resolved photoemission

TL;DR

This study uses high-resolution angle-resolved photoemission spectroscopy to clarify the topology of the Fermi surface in Bi2212, revealing a simple, hole-like structure with additional shadow and diffraction features.

Contribution

It provides the first definitive, high-resolution mapping of the normal state Fermi surface of Bi2212, resolving previous controversies and confirming its hole-like nature.

Findings

Fermi surface is hole-like with rounded tubes.

Shadow Fermi surfaces are observed.

Diffraction replicas caused by Bi-O plane modulation are identified.

Abstract

We present a study of the topology of the normal state Fermi surface (FS) of the high Tc superconductor Bi2212 using angle-resolved photoemission. We present FS mapping experiments, recorded using unpolarised radiation with high (E,k) resolution, and an extremely dense sampling of k-space. In addition, synchrotron radiation-based ARPES has been used to prove the energy independence of the FS as seen by photoemission. We resolve the current controversy regarding the normal state FS in Bi2212. The true picture is simple, self-consistent and robust: the FS is hole-like, with the form of rounded tubes centred on the corners of the Brillouin zone. Two further types of features are also clearly observed: shadow FSs, and diffraction replicas of the main FS caused by passage of the photoelectrons through the modulated Bi-O planes.