BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Surface Dynamics of Graphene and h-BN:  Molecular Mobility and Vib
 rational Energy Dissipation - Dr Anton Tamtögl\, Graz University of Techn
 ology
DTSTART:20260421T130000Z
DTEND:20260421T140000Z
UID:TALK246607@talks.cam.ac.uk
CONTACT:Boyao Liu
DESCRIPTION:Following our investigation of intercalated bilayer graphene [
 1]\, we show how intercalation can be used to decouple h-BN from a Ni(111)
  substrate\, yielding a quasi-free-standing layer. Using helium atom scatt
 ering\, we assess energy dissipation through the electron–phonon couplin
 g parameter λ and reveal how decoupling from the substrate modifies this 
 coupling. We then turn to molecular dynamics in weakly interacting systems
 \, where friction is low and motion is typically too fast to access by rea
 l-space methods [2]. Using helium spin-echo (HeSE) spectroscopy\, we ident
 ify clear differences in the nanoscale motion of both benzene and water on
  h-BN-based interfaces compared with graphene: benzene on h-BN/Ni exhibits
  a higher diffusion barrier than on graphene/Ni\, while water shows lower 
 activation energies and stronger rotational–translational coupling on h-
 BN/Ni than on graphene/Ni [3]. Together\, these results highlight how subt
 le differences in surface bonding and substrate coupling govern mobility a
 nd energy dissipation on 2D materials. More broadly\, we highlight recent 
 advances showing that HeSE can provide quantitative access to the intrinsi
 c lifetimes of low-energy surface phonons at finite wavevectors\, as demon
 strated for the Rayleigh mode on Ag(001)\, thereby opening a direct route 
 to vibrational energy dissipation at surfaces.\n\n[1] How does intercalati
 on affect the structure and dynamics of bilayer graphene? Carbon 238\, 120
 156 (2025). \n[2] Nanoscale Motion of Organic π-Conjugated Molecules: Exp
 loring van der Waals Forces\, Friction\, and Quantum Effects. Nanoscale Ho
 riz. 10\, 3158 (2025). \n[3] Understanding water behaviour on 2D material 
 interfaces through single-molecule motion on h-BN and graphene Nat. commun
 . 16\, 10465 (2025).
LOCATION:B2.002\, Ray Dolby Centre\, Cavendish Laboratory
END:VEVENT
END:VCALENDAR