Deutsch Intern
    FOR 1162

    Single-particle spectral functions for heavy fermion surface systems and coupled one-dimensional nanowires

    F. F. Assaad

    Kondo insulators arise when the heavy fermion band, dynamically generated by the screening of local moments, is  fully occupied.  Since  spin-orbit coupling   alongside  correlation effects is dominant in these compounds, the conjecture that  this  correlated state of matter can be a realization of a topological insulator has been put forward. In particular, SmB6 is a possible  candidate.  One fundamental question, of practical relevance, is  the  temperature dependence of the single particle spectral functions on topologies with edges.   We will address this question  by solving numerically  exactly a model    where the topological  Kondo  insulating state is  realized. 

    Progress in the experimental observation of heavy fermion physics hinges on realistic model calculations. We will pursue  our  collaborative effort on Ce based heavy fermion systems and further  develop our LDA+DMFT (NCA) approach for Ce based heavy fermions.  A longer term aim is to generalize these approaches to tackle ions with more than one f-electron such as Sm. 

    The ability to tailor  arrays of nano-wires  opens a new playground  to study  the physics of the dimensional crossover both triggered by charge fluctuations between the  one-dimensional conductors.   Models describing this dimensional crossover  will  be studied in the framework of the chain-DMFT approach  which is an appropriate tool to capture the one  dimensional fluctuations.  

    The dimensional driven transition from the Luttinger liquid to the Fermi liquid as well as the  dimensional driven Mott transition will be studied.