Quantum Pairing of Impurities in Quantum Crystals

Authors

Michael Tammaro, University of Rhode IslandFollow
M. P. Nightingale, University of Rhode IslandFollow
Alexander E. Meyerovich, University of Rhode IslandFollow

Document Type

Article

Date of Original Version

2-1-1993

Abstract

We calculated the time of pairing by quantum diffusion of ortho-H2 impurities in solid para-H2. The important feature of the pairing process is a strong directional bias associated with the dependence of the hopping rates on energy mismatches caused by the interaction of the pairing particles. This bias at moderate temperatures is against a mutual approach of particles and creates a ‘‘kinetic barrier.’’ At lower temperatures, the corresponding diffusion mechanism freezes out, which leads to a rapid increase in pairing rates. This explains a well-developed, experimentally observed maximum in the pairing time as a function of temperature: a maximum that exists in spite of a monotonic temperature dependence of individual hopping rates. Our results are in good agreement with experimental data.

Citation/Publisher Attribution

Tammaro, M., Nightingale, M. P., & Meyerovich, A. E. (1993), Quantum Pairing of Impurities in Quantum Crystals. Phys.Rev. B, 47(5), 2573-2580. doi: 10.1103/PhysRevB.47.2573

Available at: http://dx.doi.org/10.1103/PhysRevB.47.2573

Publisher Statement

© 1993 The American Physical Society