Related Experiment Video
Updated: Apr 24, 2026

Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids
Published on: May 27, 2020
Analysis and resolution of the ground-state degeneracy of the two-component Bose-Hubbard model
Wei Wang1, Vittorio Penna2, Barbara Capogrosso-Sansone1
1Homer L. Dodge Department of Physics and Astronomy, The University of Oklahoma, Norman, Oklahoma 73019, USA.
Abstract:
We study the degeneracy of the ground-state energy E of the two-component Bose-Hubbard model and of the perturbative correction E(1). We show that the degeneracy properties of E and E(1) are closely related to the connectivity properties of the lattice. We determine general conditions under which E is nondegenerate. This analysis is then extended to investigate the degeneracy of E(1). In this case, in addition to the lattice structure, the degeneracy also depends on the number of particles present in the system. After identifying the cases in which E(1) is degenerate and observing that the standard (degenerate) perturbation theory is not applicable, we develop a method to determine the zeroth-order correction to the ground state by exploiting the symmetry properties of the lattice. This method is used to implement the perturbative approach to the two-component Bose-Hubbard model in the case of degenerate E(1) and is expected to be a valid tool to perturbatively study the asymmetric character of the Mott insulator to superfluid transition between the particle and hole side.
Related Concept Videos
The Bohr Model
Atomic Nuclei: Nuclear Spin State Population Distribution
The Quantum-Mechanical Model of an Atom
Atomic Nuclei: Nuclear Spin State Overview
Molecular Orbital Theory II
The Pauli Exclusion Principle

