Protected nodal electron pocket from multiple-Q ordering in underdoped high temperature superconductors

Area of Science:

• Condensed Matter Physics
• Materials Science
• Solid State Physics

Background:

• Electronic structure reconstruction is crucial for understanding material properties.
• Single wave vector (Q) models often simplify complex ordering phenomena.
• Experimental observations like Fermi arcs and specific heat capacities require detailed theoretical explanations.

Purpose of the Study:

• To investigate the electronic structure resulting from multiple wave vector (Q) reconstruction.
• To compare the electronic properties of multiple-Q models with single-Q models.
• To identify protected electronic features in multiple-Q models and their potential experimental relevance.

Main Methods:

• Theoretical modeling of electronic structure using multiple wave vector (Q) reconstruction.
• Analysis of specific Q vectors, Q(x)=[2πa,0] and Q(y)=[0,2πb] with a=b=1/4.
• Comparison with experimental data from neutron diffraction and scanning tunneling microscopy.

Main Results:

• Multiple Q reconstruction yields a profoundly different electronic structure than single Q reconstruction.
• An isolated pocket adjacent to the nodal point k(nodal)=[±π/2,±π/2] is a protected feature of the multiple-Q model.
• This pocket contains electron carriers responsible for negative Hall and Seebeck coefficients.

Conclusions:

• Multiple Q reconstruction provides a more accurate description of the electronic structure in certain materials.
• The identified electronic pocket may correspond to experimentally observed nodal Fermi arcs.
• The model explains the small electronic heat capacity and anomalous transport coefficients observed in high magnetic fields.