Angle-Resolved Photoemission Spectroscopy of the Antiferromagnetic Superconductor Nd1.87Ce0.13CuO4: Anisotropic Spin-Correlation Gap, Pseudogap, and the Induced Quasiparticle Mass Enhancement

TL;DR

This study uses high-resolution ARPES to investigate the electronic structure of Nd1.87Ce0.13CuO4 near the AF-superconductor boundary, revealing anisotropic quasiparticle mass enhancement, an AF pseudogap, and temperature-dependent quasiparticle behavior.

Contribution

It provides detailed insights into the anisotropic spin-correlation gap and quasiparticle mass enhancement in an electron-doped cuprate near the AF-superconductor boundary.

Findings

Quasiparticle effective mass is strongly enhanced near (pi, 0).

The AF gap and quasiparticle mass are anisotropic.

The AF pseudogap persists above the Neel temperature.

Abstract

We performed high-resolution angle-resolved photoemission spectroscopy on Nd1.87Ce0.13CuO4, which is located at the boundary of the antiferromagnetic (AF) and the superconducting phase. We observed that the quasiparticle (QP) effective mass around (pi, 0) is strongly enhanced due to the opening of the AF gap. The QP mass and the AF gap are found to be anisotropic, with the largest value near the intersecting point of the Fermi surface and the AF zone boundary. In addition, we observed that the QP peak disappears around the Neel temperature (TN) while the AF pseudogap is gradually filled up at much higher temperatures, possibly due to the short-range AF correlation.