Enlarged Symmetry and Coherence in Arrays of Quantum Dots

TL;DR

This paper explores how arrays of quantum dots with SU(4) symmetry exhibit rich physics, including spontaneous dimerization, and demonstrates the robustness of these phases through numerical simulations, proposing experimental verification methods.

Contribution

It introduces a model of coupled quantum dots with SU(4) symmetry and shows the stability of dimerized phases using DMRG, highlighting new quantum phases in such systems.

Findings

Spontaneous dimerization occurs in SU(4) symmetric quantum dot arrays.

Dimerized phases are robust against symmetry-breaking perturbations.

Proposed experimental methods to detect the dimerized phase.

Abstract

Enlarged symmetry characterized by the group SU(4) can be realized in isolated semiconducting quantum dots. A Hubbard model then describes a pillar array of coupled dots and at half-filling the system can be mapped onto an SU(4) spin chain. The physics of these new structures is rich as novel phases are attainable. The spins spontaneously dimerize and, by using the Density Matrix Renormalization Group (DMRG), we show that the dimer state is robust to perturbations which break SU(4) symmetry. We propose ways to experimentally verify the existence of the dimerized phase.