What can Density Functional Theory tell us about Pseudogaps?

We have shown recently that advanced exchange-correlation functionals can enable first-principles treatment of the electronic, geometric and magnetic structure of the cuprates and other correlated materials without the need to invoke ad hoc parameters such as the Hubbard U. [1,2] Here, we focus on how in this picture the pseudogap phase in YBaCu3O₇ involves a large number of competing magnetic and stripe phases with small energy differences, which can be looked upon as simple antiferromagnets with topological defects, i.e. defects consisting of stacking faults and charged antiphase boundaries or the charged stripes[3,4]. A simple thermodynamic model suggests that the pseudogap consists of fluctuating short-range ordered (SRO) phases, while the strange metal corresponds to defect unbinding. The SRO phases display nematicity and Fermi arcs. Comparisons with experiment will be discussed.

[1] J. Furness et al., Nat. Commun. Phys. 11, 1 (2018).
[10] C. Lane et al,, Phys. Rev. B 98, (2018).
[3] Y. Zhang et al., arXiv:1809.08457.
[4] R.S. Markiewicz et al., arXiv:1906.05217.