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Current issue   Ukr. J. Phys. 2017, Vol. 62, N 12, p. 1024-1030
https://doi.org/10.15407/ujpe62.12.1024    Paper

Stakhira Y.M., Stakhira R.Y.

Ivan Franko National University of Lviv
(50, Dragomanov Str., Lviv 79005, Ukraine; e-mail: stakhira@electronics.lnu.edu.ua)

Structural Changes in the System of Electron States in a Shear-Deformed Layered Crystal

Section: Solid Matter
Original Author's Text: Ukrainian

Abstract: Changes in the structure of electron states in a layered crystal induced by a deformation giving rise to a relative shift of the layers have been analyzed. It is shown that if the deformation force has a low-frequency harmonic component, the period of the deformed lattice changes discretely, and the energy degeneration of the electron states becomes partially eliminated. A space-time deformation removes the energy degeneration for states, whose wave vectors have a component normal to the layer plane and equal to the component of the reciprocal lattice period in the deformed crystal along this direction. It also generates a discontinuity in the functional dependence of the energy on this component. Within a separate time period of perturbation, the energy degeneration becomes eliminated at different time moments, at which the lattice period along the shear direction is a multiple of the shift. The energies within this time interval can be identified with the use of a radio equipment, by detecting the time moments, when the density of electronic states drastically changes.

Key words:  piezophotoconductivity, layered crystals, shear deformation, periodicity change, layer shift.

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