Contrasting Pathways to Mott Gap Collapse in Electron and Hole Doped Cuprates

TL;DR

This paper compares how the Mott gap closes in electron- and hole-doped cuprates, revealing different pathways but a common collapse near optimal doping, supported by ARPES data and mode coupling calculations.

Contribution

It introduces a mean field model and mode coupling calculations that explain the contrasting doping behaviors in electron- and hole-doped cuprates.

Findings

Mott gap closes near optimal doping in electron-doped cuprates.

Hole-doped cuprates exhibit instability toward spiral or stripe phases.

Magnetic order collapses near optimal doping in both cases.

Abstract

Recent ARPES measurements on the electron-doped cuprate Nd_{2-x}Ce_xCuO_4 can be interpreted in a mean field model of uniform doping of an antiferromagnet, with the Mott gap closing near optimal doping. Mode coupling calculations confirm the mean field results, while clarifying the relation between the Mott gap and short-range magnetic order. The same calculations find that hole doped cuprates should follow a strikingly different doping dependence, involving instability toward spiral phases or stripes. Nevertheless, the magnetic order (now associated with stripes) again collapses near optimal doping.