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Low-energy quantum dynamics of atoms at defects. Interstitial oxygen in silicon

Rafael Ramirez·Carlos P. Herrero·Emilio Artacho·Felix Yndurain
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Abstract

The problem of the low-energy highly-anharmonic quantum dynamics of isolated impurities in solids is addressed by using path-integral Monte Carlo simulations. Interstitial oxygen in silicon is studied as a prototypical example showing such a behavior. The assignment of a "geometry" to the defect is discussed. Depending on the potential (or on the impurity mass), there is a "classical" regime, where the maximum probability-density for the oxygen nucleus is at the potential minimum. There is another regime, associated to highly anharmonic potentials, where this is not the case. Both regimes are separated by a sharp transition. Also, the decoupling of the many-nuclei problem into a one-body Hamiltonian to describe the low-energy dynamics is studied. The adiabatic potential obtained from the relaxation of all the other degrees of freedom at each value of the coordinate associated to the low-energy motion, gives the best approximation to the full many-nuclei problem.

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Rafael Ramirez, Carlos P. Herrero, Emilio Artacho, Felix Yndurain. 1996-07-30. Low-energy quantum dynamics of atoms at defects. Interstitial oxygen in silicon. https://doi.org/10.1088/0953-8984%2F9%2F15%2F004

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