Z_{2} fractionalized phases of a solvable disordered t J model
Abstract
We describe the phases of a solvable t J model of electrons with infiniterange, and random, hopping, and exchange interactions, similar to those in the SachdevYeKitaev models. The electron fractionalizes, as in an "orthogonal metal," into a fermion f , which carries both the electron spin and charge, and a boson ϕ . Both f and ϕ carry emergent Z_{2} gauge charges. The model has a phase in which the ϕ bosons are gapped, and the f fermions are gapless and critical, and so the electron spectral function is gapped. This phase can be considered as a toy model for the underdoped cuprates, without spatial structure. The model also has an extended, critical, "quasiHiggs" phase where both ϕ and f are gapless, and the electron operator ∼f ϕ has a Fermi liquidlike 1 /τ propagator in imaginary time, τ . So while the electron spectral function has a Fermi liquid form, other properties are controlled by Z_{2} fractionalization and the anomalous exponents of the f and ϕ excitations. This quasiHiggs phase is proposed as a toy model of the overdoped cuprates. We also describe the critical state separating these two phases.
 Publication:

Physical Review B
 Pub Date:
 August 2018
 DOI:
 10.1103/PhysRevB.98.075150
 arXiv:
 arXiv:1804.04130
 Bibcode:
 2018PhRvB..98g5150F
 Keywords:

 Condensed Matter  Strongly Correlated Electrons;
 High Energy Physics  Theory
 EPrint:
 30 pages, 9 figures