Quantum stabilization of atomically flat films of Pb at 300 K (Charla Invitada)

CALLEJA, F.; HINAREJOS, J.J.; PASSEGGI (JR.), M.C.G.; LOPEZ VAZQUEZ DE PARGA, A.; MIRANDA, R.

London, United Kingdom, 27-29 June

Conferencia; UK SPM 2006, Microscience 2006; 2006

Royal Microscopical Society

The dynamics of the thermal evolution of films of different thicknesses is explored by movies recorded with a Variable Temperature STM and compared to electronic energy calculations. We find that each Pb thickness becomes unstable at a different temperature related to their total energy. Films with QWS at the Fermi level (such as 9 ML-thick) are particularly unstable, while layers with thickness corresponding to “magic heights” are substantially more stable. For certain thicknesses the energy barriers to adjacent heights are particularly large, giving rise to metastable but atomically flat films of Pb over micron scales, even at 300 K. This effect is another manifestation of macroscopic quantum effects at room temperature. (Expuso Fabián Calleja)