Optical and spectral properties of quantum domain walls in the generalized Wigner lattice

Simone Fratini (1) , G. Rastelli (2)

1 NEEL - TMC - Théorie de la Matière Condensée
2 Istituto dei Sistemi Complessi

We study the spectral properties of a system of electrons interacting through long-range Coulomb potential on a one-dimensional chain. When the interactions dominate over the electronic bandwidth, the charges arrange in an ordered configuration that minimizes the electrostatic energy, forming Hubbard's generalized Wigner lattice. In such strong-coupling limit, the low-energy excitations are quantum domain walls that behave as fractionalized charges and can be bound in excitonic pairs. Neglecting higher-order excitations, the system properties are well described by an effective Hamiltonian in the subspace with one pair of domain walls, which can be solved exactly. The optical conductivity σ(ω) and the spectral function A(k,ω) can be calculated analytically and reveal unique features of the unscreened Coulomb interactions that can be directly observed in experiments.

Domaines: Electrons fortement corrélés [cond-mat.str-el]

Simone Fratini, G. Rastelli. Optical and spectral properties of quantum domain walls in the generalized Wigner lattice. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2007, 75, pp.195103. ⟨10.1103/PhysRevB.75.195103⟩. ⟨hal-00704939⟩