Theory for self-trapped holes in rare-gas solids. II. Systematic change in the series of Ne to Xe and its physical origin

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Abstract
The calculation of self-trapped holes in rare-gas solids proposed by the present author is extended to Kr, Xe, and Ne in order to study how the self-trapped state is changed in the series of Ne to Xe. The following results are obtained. (i) The most energetically favorable configuration for the self-trapped state is either the simplest one-center or the simplest two-center trapped state with the large lattice contraction around the trapped center(s). (ii) The self-trapped state for Ne, Ar, and Kr is stable compared with a valence-band free-hole state, while the self-trapped state in Xe may be metastable or nearly on the stability boundary, which is well correlated to the temperature dependence of the mobility data of the valence holes. (iii) The possibility of self-trapping and the magnitude of the main lattice displacements for the self-trapped state decrease systematically in the series of Ne to Xe. From an analysis of the result obtained, the essential importance of the nonlinear effect of the hole-lattice interaction can be deduced. The systematic change in the series of Ne to Xe revealed by the calculation is clearly understood in terms of this nonlinear effect, and is shown to be directly related to the systematic change of the extension of the valence p atomic wave function (from Ne to Xe) together with the short-range nature of the atomic potential in rare-gas solids.