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arXiv · 2607.14221

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
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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.

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Cesar A. Gallegos, Andrew J. Millis, Steven R. White. 2026-07-15. Spinless charged excitation at the interface between a conventional topological insulator and a topological Mott insulator. https://arxiv.org/abs/2607.14221

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