Dynamical Coulomb Blockade Effect in Ultra-Low-Temperature Scanning Tunneling Spectroscopy : Understanding, Correction, and Application to Atomic-Layer Thin Films

Scanning tunneling spectroscopy at ultra-low temperatures probes the electronic states of atomic-layer materials, but its resolution is often limited by the dynamical Coulomb blockade (DCB) : tunneling electrons exchange energy with the surrounding electromagnetic environment via the P(E) function. Because atomic-layer films and nanoscale islands have extremely small junction capacitances, this effect becomes pronounced, and the measured dI/dV spectrum reflects not the intrinsic local density of states (LDOS) but its convolution with P(E), which can be misidentified as an intrinsic pseudogap or altered quasiparticle lifetime. This article outlines the physical origin of DCB in the tip–film–substrate junction and presents a correction method, using normal-state spectra under magnetic field to determine P(E) and recover the intrinsic LDOS.