Hidden Charge 2e Boson in Doped Mott Insulators: Field Theory of Mottness

TL;DR

This paper develops a low-energy field theory for doped Mott insulators, revealing a charge 2e boson that influences spectral properties and creates new excitations, explaining recent ARPES observations.

Contribution

It introduces a novel low-energy effective theory showing the emergence of a charge 2e boson in doped Mott insulators, linking it to spectral features and electron dispersion bifurcation.

Findings

Charge 2e boson mediates spectral weight transfer.

Creates a new charge e excitation by binding a hole.

Explains bifurcation of electron dispersion observed in ARPES.

Abstract

We construct the low energy theory of a doped Mott insulator, such as the high-temperature superconductors, by explicitly integrating over the degrees of freedom far away from the chemical potential. For either hole or electron doping, a charge 2e bosonic field emerges at low energy. The charge 2e boson mediates dynamical spectral weight transfer across the Mott gap and creates a new charge e excitation by binding a hole. The result is a bifurcation of the electron dispersion below the chemical potential as observed recently in angle-resolved photoemission on Pb-doped Bi_2Sr_2CaCu_2O_{8+\delta} (Pb2212).