QDev Seminar: Jongbae Hong – University of Copenhagen

QDev Seminar: Jongbae Hong

Tunneling Conductance Formula for Strongly Correlated Materials

Tunneling conductance measurements such as two-terminal transport and scanning tunneling microscopy are important tools for the characterization of condensed matter systems. However, for strongly correlated materials, the tunneling mechanism has not yet been theoretically reproduced, or adequately explained. This is because the combination of strong electron–electron interactions and the non-equilibrium nature of the problem is poorly understood. We show that a new theory for the tunneling conductance for strongly correlated systems can explain all the features of experimental tunneling conductance for many different materials such as a quantum dot single-electron transistor, a quantum point contact, a magnetic atom adsorbed on a metal surface, bilayer graphene, and ABC-stacked trilayer graphene. In particular, our theory gives a quantitative fit and a qualitative explanation for the side peaks which are present in many different experimental data, but which are not explained by any prior theory. Finally, our theory also allows the extraction of the density of states of the strongly correlated material: a quantity which is often very hard to derive from theoretical considerations.