Topological Insulators Effects of spin on transport of electrons in solids
SPIN • Mott insulators • Rashba effect • Superconductivity • Quantum information and computation
Topological insulator • Exhibits insulating behaviour in the bulk but has conducting edge or surface states • So far the only models exploit spin-orbit interactions • is generally related to introducing a time-reversal-symmetry breaking interaction, as is the case for SO. • Existence established in some systems from ARPES experiments
Rashba effect • Spin-orbit coupling-like potential
Cases • A gap is produced • For the gap is • Quantized Hall conductivity: • BUT! It will vanish for
Gapless edge states • At the edges opposite spins travel opposite directions. (Kane et al) • At low energy
Observation • Graphene SO effects very small, hard to observe • Bi1-xSbx Observed! Surface states instead of edge states • Using ARPES
Promises • Topological states robust to perturbation • Stable qubits for Quantum Computation • Dissipation-less spin current transport good for Spintronics new SuperConductivity-like effects to be observed, I presume. Not literally.