Correlation Effects in Quantum Spin-Hall Insulators: A Quantum Monte Carlo Study

Understand

We consider the Kane-Mele model with spin-orbit coupling supplemented by a Hubbard U term.

• On the basis of projective auxiliary field quantum Monte Carlo simulations on lattice sizes up to 15 x 15, we map out the phase diagram.
• The quantum spin-liquid state found in the Hubbard model is shown to be robust against weak spin-orbit interaction, and is not adiabatically connected to the spin-Hall insulating state.
• Beyond a critical value of U > U_c both states are unstable toward magnetic ordering.