Imperial College London

Matthew Foulkes

Faculty of Natural SciencesDepartment of Physics

Professor of Physics



+44 (0)20 7594 7607wmc.foulkes Website




Mrs Carolyn Dale +44 (0)20 7594 7579




810Blackett LaboratorySouth Kensington Campus






BibTex format

author = {Lim, A and Foulkes, WM and Horsfield, AP and Mason, DR and Schleife, A and Draeger, EW and Correa, AA},
doi = {10.1103/PhysRevLett.116.043201},
journal = {Physical Review Letters},
title = {Electron elevator: excitations across the band gap via a dynamical gap state},
url = {},
volume = {116},
year = {2016}

RIS format (EndNote, RefMan)

AB - We use time-dependent density functional theory to study self-irradiated Si. We calculate the electronic stopping power of Si in Si by evaluating the energy transferred to the electrons per unit path length by an ion of kinetic energy from 1 eV to 100 keV moving through the host. Electronic stopping is found to be significant below the threshold velocity normally identified with transitions across the band gap. A structured crossover at low velocity exists in place of a hard threshold. An analysis of the time dependence of the transition rates using coupled linear rate equations enables one of the excitation mechanisms to be clearly identified: a defect state induced in the gap by the moving ion acts like an elevator and carries electrons across the band gap.
AU - Lim,A
AU - Foulkes,WM
AU - Horsfield,AP
AU - Mason,DR
AU - Schleife,A
AU - Draeger,EW
AU - Correa,AA
DO - 10.1103/PhysRevLett.116.043201
PY - 2016///
SN - 1079-7114
TI - Electron elevator: excitations across the band gap via a dynamical gap state
T2 - Physical Review Letters
UR -
UR -
UR -
VL - 116
ER -