University of Vermont

Office of Undergraduate Research

Electronic Conduction at the Edge

Edge States
Nuclear spins can flip electron spins at the conducting edge of a topological insulator.

An international team of researchers including Prof. Adrian Del Maestro at the University of Vermont may have uncovered a way to improve the efficiency of proposed future electronics built from the edges of a new class of exotic materials.  In conventional electronic circuitry, electrons move through crystalline wires but their flow is impeded by scattering off defects producing a finite resistance.  Topotronics employ quantum mechanical degrees of freedom which allow for highly conducting dissipation free channels at the surface of materials which would otherwise be insulating in their bulk. In a paper appearing in the journal Physical Review B, Prof. Del Maestro and his collaborators have shown that the spin polarization of electrons at the surface of a topological insulator made from mercury and tellurium makes them susceptible to a different type of scattering due to the magnetic interaction between electrons and the fixed mercury nuclei.  By building topotronics with isotopes that do not contain any nuclear spins, conducting wires could made with vanishingly small electrical resistance leading to applications including better batteries and more efficient computers.