Wannier-Stark states in double-periodic lattices. II. Two-dimensional lattices

Описание

Тип публикации: статья из журнала

Год издания: 2015

Идентификатор DOI: 10.1103/PhysRevA.91.053632

Ключевые слова: Wave packets, Arbitrary superposition, Asymptotic expressions, In-laboratory experiments, Intermediate fields, Localized wave packets, Packet dispersion, Translation vector, Two-dimensional lattices, Band structure

Аннотация: We analyze the Wannier-Stark spectrum of a quantum particle in tilted two-dimensional lattices with the Bloch spectrum consisting of two subbands, which could be either separated by a finite gap or connected by the Dirac points. For rational orientations of the static field given by an arbitrary superposition of the translation vecПоказать полностьюtors, the spectrum is a ladder of energy bands. We obtain asymptotic expressions for the energy bands in the limit of large and weak static fields and study them numerically for intermediate field strength. We show that the structure of energy bands determines the rate of spreading of localized wave packets, which is the quantity measured in laboratory experiments. It is shown that wave-packet dispersion becomes a fractal function of the field orientation in the long-time regime of ballistic spreading.

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Издание

Журнал: PHYSICAL REVIEW A

Выпуск журнала: Vol. 91, Is. 5

ISSN журнала: 10502947

Место издания: COLLEGE PK

Издатель: AMER PHYSICAL SOC

Персоны

  • Maksimov D.N. (Kirensky Institute of Physics)
  • Bulgakov E.N. (Siberian State Aerospace University)
  • Kolovsky A.R. (Siberian Federal University)