From (violation of) empirical laws → Physics: connecting non-equilibrium phenomena to atomic jiggling

by Guilherme Vilhena (Materials Science Institute of Madrid (ICMM), Spanish National Research Council (CSIC))

Wednesday 12 Nov 2025, 14:00 → 15:00 Portugal

Sala de Conferências (Departamento de Física FCTUC)

Non-equilibrium physical processes remain one of the major open challenges in physics. At the macroscale, our understanding of these systems relies heavily on empirical laws derived from observation rather than fundamental universal principles. However, at the nanoscale, these laws break down, giving rise to novel exotic phenomena that open new opportunities for designing materials with unprecedented properties.
In this talk, we focus on two key non-equilibrium processes – friction and heat transport – which together account for over 30% [1, 2] of global energy consumption. Using atomistic simulations in synergy with experiments, we explore how the breakdown of their empirical macroscale laws reveals new emergent physics, linking the "wiggling and jiggling" of atoms [3] to novel mechanisms. Specifically, we demonstrate [4] how a surprising violation of the first law of friction enables the control of ultra-low friction states (superlubricity). Likewise, we show [5] that the breakdown of Fourier’s law reveals both superdiffusive heat transport and phonon interference, both manifestations of the wave-like nature of heat, in an unprecedented parallel to the double-slit experiments that revealed the wave–particle duality of light, now realized for phonons.

References:
[1] Holmberg et al. Friction 5, 263 (2017)
[2] Cooper et al. Nature Energy 8, pp. 1328 (2023)
[3] Feynman, R. Engineering & Science 23, 22–36 (1960)
[4] Vilhena et al. Physical Review Letters 128 , 216102 (2022) ; Nano Letters 23, 4693 (2023); Physical Review X 9 , 041045 (2019); ACS Nano 19, 13805 (2025)
[5] Nature Communications 16, 7342 (2025) ; Nature Materials 24, 1258 (2025);