Spin-density wave fermi surface reconstruction in underdoped YBa2Cu3O6+x

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Materials

Background:

• Underdoped cuprates, such as Yttrium Barium Copper Oxide (YBa2Cu3O6+x), exhibit complex electronic properties.
• Understanding the Fermi surface topology is crucial for explaining phenomena like superconductivity and quantum oscillations in these materials.

Purpose of the Study:

• To reconstruct the Fermi surface of underdoped YBa2Cu3O6+x.
• To investigate the implications of a collinear spin-density wave (SDW) model on the Fermi surface.
• To compare theoretical predictions with experimental observations, including quantum oscillations and effective mass.

Main Methods:

• Modeling the Fermi surface based on a collinear spin-density wave with a specific wave vector Q = (pi[1 +/- 2delta],pi).
• Incorporating an incommensurability parameter delta ≈ 0.06, informed by neutron scattering data.
• Analyzing quantum oscillation frequencies and quasiparticle effective masses.

Main Results:

• A Fermi surface reconstruction consistent with multiple observed quantum oscillation frequencies was achieved.
• The model indicates a uniform enhancement of the quasiparticle effective mass by a factor of approximately 7.
• Discrepancies between calculated low band masses and experimental values suggest this significant mass enhancement.

Conclusions:

• The proposed spin-density wave model provides a plausible explanation for the Fermi surface of underdoped YBa2Cu3O6+x.
• The predicted Fermi surface topology and mass enhancement offer avenues for experimental verification.
• Further experiments can validate the relevance of this model to the electronic behavior of underdoped cuprates.