TY - JOUR
T1 - Phonon-assisted tunneling of adatoms on a solid surface
T2 - The influence of quadratic adatom-phonon couplings
AU - Zhu, X. D.
AU - Deng, L.
PY - 1993
Y1 - 1993
N2 - We investigate the influence of quadratic adatom-phonon couplings on the phonon-assisted adatom tunneling on solids based upon the early work of Tonks and Dick. We find that the incoherent tunneling at high temperatures (TTD/3) is not simply thermally activated but described by a rate ij(Latin small letter h with stroke)2exp[-Ea/kBT+Ea2/(kBT)2] where is the renormalized tunneling matrix element, Ea is the conventional activation energy caused by linear adatom-phonon couplings, and Ea is an effective energy arising from the quadratic couplings. We determine the conditions when the activated tunneling behavior is qualitatively altered by the quadratic couplings. As a result of reduced dimensionality, the latter play much more important roles in the tunneling diffusion of hydrogen on metal surfaces than they do in the interstitial tunneling in solids.
AB - We investigate the influence of quadratic adatom-phonon couplings on the phonon-assisted adatom tunneling on solids based upon the early work of Tonks and Dick. We find that the incoherent tunneling at high temperatures (TTD/3) is not simply thermally activated but described by a rate ij(Latin small letter h with stroke)2exp[-Ea/kBT+Ea2/(kBT)2] where is the renormalized tunneling matrix element, Ea is the conventional activation energy caused by linear adatom-phonon couplings, and Ea is an effective energy arising from the quadratic couplings. We determine the conditions when the activated tunneling behavior is qualitatively altered by the quadratic couplings. As a result of reduced dimensionality, the latter play much more important roles in the tunneling diffusion of hydrogen on metal surfaces than they do in the interstitial tunneling in solids.
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U2 - 10.1103/PhysRevB.48.17527
DO - 10.1103/PhysRevB.48.17527
M3 - Article
AN - SCOPUS:25944439966
VL - 48
SP - 17527
EP - 17532
JO - Physical Review B-Condensed Matter
JF - Physical Review B-Condensed Matter
SN - 0163-1829
IS - 23
ER -