Quantum confinement effects can induce the formation of discrete nanostructures with well-
defined preferred heights in thin metallic films. In most systems, such electronic growth
modes are weak and limited to cryogenic conditions. Recently, however, we have
discovered that metals grown upon van der Waals surfaces can exhibit electronic growth at,
or even above, room temperature to spontaneously form well-defined and highly stable
nanostructures. Here, we explore the initial stages of room temperature deposition of Pd …