Enlarged Symmetry and Coherence in Arrays of Quantum Dots
Abstract
Description
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.
8 pages, 7 EPS figures. Version to appear in Physical Review B
8 pages, 7 EPS figures. Version to appear in Physical Review B