Tuning between a fractional topological insulator and competing phases at nu_T=2/3
by
WHGA/121
hybrid via Teams: Meeting ID: 384 671 337 326 7 Passcode: eB2jh2QV
We study a spinful, time-reversal symmetric lowest Landau level model for a flatband quantum spin Hall system at total filling fraction nu_T=2/3. Such models are relevant, e.g., for spin-valley locked moiré transition metal dichalcogenides. The opposite Chern number of the two spins hinders the formation of a quantum Hall ferromagnet, instead favouring other phases. We study the phase diagram in dependence on different short-range Haldane pseudopotentials v_m and uncover several phases: A fractional topological insulator, a phase separated state, a spin-polarized fractional quantum Hall state, and the partially particle-hole transformed Halperin (111) state. The effect of the pseudopotentials v_m depends on the parity of m, the relative angular momentum.
Referenz: arXiv:2506.20720.
Laboratory for Theoretical and Computational Physics