Spinless charged excitation at the interface between a conventional topological insulator and a topological Mott insulator

Cesar A. Gallegos; Andrew J. Millis; Steven R. White

Spinless charged excitation at the interface between a conventional topological insulator and a topological Mott insulator

Strongly Correlated Electrons 2026-07-15 v1

Authors: Cesar A. Gallegos , Andrew J. Millis , Steven R. White

Abstract

We investigate the interface separating two topologically distinct insulating phases of matter using extensive density-matrix renormalization group calculations to study the triangular-lattice Hofstadter-Hubbard model with a spatially varying interaction strength, chosen to realize both integer quantum Hall and chiral spin liquid states in different spatial regions. We find that the integer quantum Hall-chiral spin liquid interface hosts a spinless charged excitation that is bound to the interface. This mode at the interface is identified through charge and spin pumping, and by direct calculations of low-lying excited states. We also characterize bulk excitations in both phases, finding evidence for fractionalization in the chiral spin liquid and for spin-triplet exciton formation in the integer quantum Hall phase.

Keywords

topological insulator topological Mott insulator interface chiral spin liquid integer quantum Hall density-matrix renormalization group

Cite

@article{arxiv.2607.14221,
  title  = {Spinless charged excitation at the interface between a conventional topological insulator and a topological Mott insulator},
  author = {Cesar A. Gallegos and Andrew J. Millis and Steven R. White},
  journal= {arXiv preprint arXiv:2607.14221},
  year   = {2026}
}

Comments

5+1 pages, 5+2 figures