Magnetic response in quantized spin hall phase of correlated electrons

We investigate the magnetic response in the quantized spin Hall (SH) phase of a layered-honeycomb lattice system with intrinsic spin-orbit coupling λSO and on-site Hubbard U. The response is characterized by the parameter g= 4Ua2d/3, where a and d are the lattice constant and interlayer distance, respectively. When g < (σxys2μ)-1, where σxys is the quantized spin Hall conductivity and μ is the magnetic permeability, the magnetic field inside the sample oscillates spatially. The oscillation vanishes in the non-interacting limit U → 0. When g > (σxys2μ)-1, the system shows perfect diamagnetism, i.e., the Meissner effect occurs. We find that a superlattice structure with large a is favorable for observing these phenomena. We also point out that, as a result of Zeeman coupling, the topologically protected helical edge states show weak diamagnetism that is independent of g. (author)