Quantum Tunneling Insights into the Atomic Landscapes of Graphite, Gold, and Silicon

Abstract

Scanning Tunneling Microscopy (STM) is a powerful technique that utilizes quantum tunneling to visualize atomic surfaces with high precision. This study presents detailed topographic maps and evaluates the local density of states (LDOS) for three distinct materials: Highly Oriented Pyrolytic Graphite (HOPG), gold, and silicon. By meticulously measuring the tunneling current from a finely pointed tip positioned nanometers above the sample, we successfully image the surface topography of HOPG, revealing a lattice constant of $0.28 \pm 0.01$ nm. Additionally, we determine the local work functions for gold and graphite to be $0.7 \pm 0.1$ eV and $0.5 \pm 0.1$ eV, respectively. Employing scanning tunneling spectroscopy, this work further investigates the LDOS for gold (a metal), graphite (a semi-metal), and silicon (a semiconductor), providing valuable insights into their electronic properties at the atomic level.