Fermi Surface Evolution in an Electron-Doped High-Tc Superconductor Revealed by Magnetic Quantum Oscillations

Abstract

We report on the direct probing of the Fermi surface in the bulk of the electron-doped superconductor Nd${}_{2-x}$Ce${}_x$CuO${}_4$ at different doping levels by means of magnetoresistance quantum oscillations. Our data reveal a sharp qualitative change in the Fermi surface topology, due to translational symmetry breaking in the electronic system which occurs at a critical doping level significantly exceeding the optimal doping. This result implies that the $(\ddot{I}€/a,\ddot{I}€/a)$ ordering, known to exist at low doping levels, survives up to the overdoped superconducting regime.

12 pages, 4 figures; submitted to PRL