Operatorial formulation of the ghost rotationally-invariant slave-Boson theory

TL;DR

This paper introduces an operatorially exact formalism called ghost rotationally-invariant slave-Boson theory (g-RISB) for analyzing many-electron systems, unifying and extending previous approaches to include quantum fluctuations and dynamics.

Contribution

The paper develops a novel operatorially exact formalism (g-RISB) that generalizes existing mean-field theories and enables systematic inclusion of quantum fluctuations in many-electron lattice systems.

Findings

Reduces to ghost Gutzwiller approximation at mean-field level

Introduces a time-dependent g-RISB action for dynamics

Potential for systematic quantum fluctuation corrections

Abstract

We propose an operatorially-exact formalism for describing the equilibrium and quantum-dynamical properties of many-electron systems interacting locally on a lattice, called "ghost rotationally-invariant slave-Boson theory" (g-RISB). We demonstrate that our theoretical framework reduces to the recently-developed ghost Gutzwiller approximation (g-GA) at the mean-field level. Furthermore, we introduce the time-dependent mean-field g-RISB action, generalizing the time-dependent GA theory. Since the g-RISB is based on exact reformulation of the many-body problem, it may pave the way to the development of practical implementations for adding systematically quantum-fluctuation corrections towards the exact solution, in arbitrary dimension.