Singularity in self-energy and composite fermion excitations of interacting electrons

Abstract

We propose that a composite fermion operator $f_{i\sigma }(2n_{i\bar{\sigma }}-1)$ could have coherent excitations, where $f_{i\sigma }$ is the fermion operator for interacting electrons and $n_{i\bar{\sigma }}$ is the number operator of the opposite spin. In the two-impurity Anderson model, it is found that the excitation of this composite fermion has a pseudogap in the Kondo regime, and has a finite spectral weight in the regime where the excitation of the regular fermion $f_{i\sigma }$ has a pseudogap. In the latter regime, the self-energy of $f_{i\sigma }$ is found to be singular near Fermi energy. We argue that this composite fermion could develop a Fermi surface with Fermi liquid behaviors but "hidden" from charge excitations in lattice generalizations. We further illustrate that this type of excitations is essential in addressing the pseudogap state and unconventional superconductivity.

10 pages, 6 figures

References in corpus (16)

• The numerical renormalization group method for quantum impurity systems
• Strong Correlations and Magnetic Frustration in the High Tc Iron Pnictides
• Heavy Fermions and Quantum Phase Transitions
• A Phenomenological Theory of The Pseudogap State
• Spin Precession and Real Time Dynamics in the Kondo Model: A Time-Dependent Numerical Renormalization-Group Study
• A Phenomenological Theory of the Anomalous Pseudogap Phase in Underdoped Cuprates
• Doped high-Tc cuprate superconductors elucidated in the light of zeros and poles of electronic Green's function
• Orbital-selective Mott transitions: Heavy fermions and beyond
• The Hubbard model within the equations of motion approach
• Composite-Fermion Theory for Pseudogap, Fermi Arc, Hole Pocket, and Non-Fermi-Liquid of Underdoped Cuprate Superconductors
• Hidden Fermi Liquid: Self-Consistent Theory for the Normal State of High-Tc Superconductors
• Cofermion Theory for Pseudogap Phenomena and Superconducting Mechanism of Underdoped Cuprate Superconductors
• Coherence scale of coupled Anderson impurities
• Mott physics, sign structure, ground state wavefunction, and high-Tc superconductivity
• Magnetic field induced quantum phase transitions in the two-impurity Anderson model
• Superconducting pairing of interacting electrons: implications from the two-impurity Anderson model

Cited by in corpus (6)

• Evidence for hidden fermion that triggers high-temperature superconductivity in cuprates
• Direct Connection between Mott Insulator and d-Wave High-Temperature Superconductor Revealed by Continuous Evolution of Self-Energy Poles
• Excitons and Dark Fermions as Origins of Mott Gap, Pseudogap and Superconductivity in Cuprate Superconductors --- General Idea and Basic Concept Based on Gap Physics
• Charge dynamics of correlated electrons: Variational description with inclusion of composite fermions
• Pairing Correlations Near a Kondo-Destruction Quantum Critical Point
• Unconventional orbital ordering and emergent dimensional reduction in fulleride superconductors