Condensed Matter Seminars

The  quantum  spin  Hall  insulator, also  known  as  a  two-dimensional  (2D) topological  insulator,  is  a  topological  state  of  matter  supporting  the  helical edge states, which are counter-propagating, spin-momentum locked 1D modes protected  by  time  reversal  symmetry. It  exhibits  special  magneto-transport properties under external magnetic field. In my talk, I will construct modified Anderson impurity models to study the magneto-conductance of the quantum spin hall insulator. Firstly, I will solve the transmission through single impurity on helical Luttinger liquid in the presence of magnetic field using Lippmann-Schwinger equation.  I will show the analytical expression for trans- mission and reflection coefficient in terms of the difference between energy of particle and the impurity level, the hybridization coefficient and the magnetic field. Then, I will show the effect of Coulomb interaction on helical Luttinger liquid at Hartree-Fock level. Using renormalization group, I will derive the temperature dependence of conductance.  Lastly, I will show the coherent transport of transmission through many impurities with different energy and hybridization coefficient in the presence of magnetic field.  I will compare my theoretical result with experiment.