Physics

Dr. Biswajit Karmakar
Saha Institute of Nuclear Physics, Kolkata

Abstract: Integer quantum Hall (IQH) states which are well understood in terms of non-interacting electrons are expected to have dissipation-less edge states transport from protected integer charge modes with conductance of /h. However, in strong Coulomb interaction regime, nucleation of dominant fractional quantum Hall (FQH) gaps at filling ν  = 1/3 and 2/3 gives rise to incompressible strips around the smooth boundary of IQH system. As a consequence, edge states of IQH system become fractionalized into three downstream charge modes of conductance /3h each. In this talk I shall present the edge state fractionalization at long mesa boundary of ν = 1 IQH states in high mobility 2DEG. We experimentally demonstrate that ν = 1 IQH edge state is composed of three robust downstream fractional 1/3 charge modes. Equilibration between the modes can be controlled by tuning the magnetic field within the extent of ν = 1 IQH plateau. In our experiment, we could unveil the equilibration properties of the modes and this finding is linked to formation of the two set of fractional conductance plateaus of values 1/9, 2/9, 4/9 and 1/6, 1/3, 2/3 at the two ends of ν = 1 IQH plateau under selective excitation and detection of the fractionalized1/3 modes.