Spin-stripe density varies linearly with hole content in single-layer Bi2201 cuprate

TL;DR

This study investigates how spin-stripe density in Bi2201 cuprate varies linearly with hole content, revealing changes in spin fluctuations and incommensurate modulation across doping levels, with implications for understanding high-temperature superconductivity.

Contribution

It demonstrates a linear relationship between spin-stripe incommensurability and hole doping in Bi2201, and compares spin correlations with La2-xSrxCuO4.

Findings

Incommensurate wave vector shifts with doping

Linear relation between incommensurability and hole content

Suppressed spectral weight below 4 meV in superconducting regime

Abstract

We have performed inelastic neutron scattering measurements on the single-layer cuprate Bi2+xSr2-xCuO6+y (Bi2201) with x=0.2, 0.3, 0.4 and 0.5, a doping range that spans the spin-glass (SG) to superconducting (SC) phase boundary. The doping evolution of low energy spin fluctuations was found to be characterized by a change of incommensurate modulation wave vector from the tetragonal [110] to [100]/[010] directions, while maintaining a linear relation between the incommensurability and the hole concentration, delta p. In the SC regime, the spectral weight is strongly suppressed below 4 meV. Similarities and differences in the spin correlations between Bi2201 and the prototypical single-layer system La2-xSrxCuO4 are discussed.