Infrared catastrophe and tunneling into strongly correlated electron systems: Perturbative x-ray edge limit
Infrared catastrophe and tunneling into strongly correlated electron systems: Perturbative x-ray edge limit
The tunneling density of states exhibits anomalies (cusps, algebraic suppressions, and pseudogaps) at the Fermi energy in a wide variety of low-dimensional and strongly correlated electron systems. We argue that in many cases these spectral anomalies are caused by an infrared catastrophe in the screening response to the sudden introduction …