Research in the Gweon Group
Anomalous nodal many body density of states
LThe density of states (DOS) is a basic quantity, e.g., for describing free electrons in a solid. As the name suggests, it says how many electrons the material can accomodate at a certain energy value.
In a strongly correlated electron system such as high temperature superconductors, the equivalent quantity is the many body density of states (MBDOS), $\int d\vec k A(\vec k, \omega)$, where $A$ is the single particle spectral function, measured by ARPES. Even when the DOS is predicted to be finite at the Fermi energy (“band metal”), strong correlation can lead to a vanishing MBDOS (“Mott-Hubbard insulator”).
A very important question that has been very tough to answer so far is “does the Mott insulator physics have a distinctive signature in near the optimally doped high temperature superconductor?”