Exact Solution of a Two-Species Quantum Dimer Model for Pseudogap Metals

Area of Science:

• Condensed Matter Physics
• Quantum Materials
• Superconductivity

Background:

• The pseudogap phase in high-temperature cuprate superconductors remains a complex area of research.
• Quantum dimer models offer a theoretical framework to understand emergent phenomena in strongly correlated electron systems.
• Understanding the interplay of spinons, holons, and emergent Fermi surfaces is crucial.

Purpose of the Study:

• To find an exact ground state solution for a specific quantum dimer model.
• To investigate the model's relevance to the metallic pseudogap phase in cuprates.
• To characterize the emergent electronic states at varying densities of fermionic dimers.

Main Methods:

• Exact diagonalization of a quantum dimer model.
• Construction of ground state wave functions along a specific parameter line.
• Analysis of ground state degeneracy and fermionic excitations.
• Perturbative analysis around the exactly solvable line.

Main Results:

• An exact ground state solution was found for the quantum dimer model.
• A line in parameter space allows for the construction of exact ground state wave functions.
• The exactly solvable line exhibits a large ground state degeneracy, interpreted as a flat band of fermionic excitations.
• Perturbations lead to a fractionalized Fermi liquid with a small pocket Fermi surface at low doping.

Conclusions:

• The quantum dimer model successfully captures key properties of the pseudogap metal.
• The identified exactly solvable line provides a novel pathway to study emergent fermionic states.
• The research elucidates the emergence of a fractionalized Fermi liquid from a highly degenerate ground state.