Wannier-Stark resonances in semiconductor superlattices

Abstract

Wannier-Stark states for semiconductor superlattices in strong static fields, where the interband Landau-Zener tunneling cannot be neglected, are rigorously calculated. The lifetime of these metastable states was found to show multiscale oscillations as a function of the static field, which is explained by an interaction with above-barrier resonances. An equation, expressing the absorption spectrum of semiconductor superlattices in terms of the resonance Wannier-Stark states, is obtained and used to calculate the absorption spectrum in the region of high static fields.

Instability of dynamic localization in the intense terahertz-driven semiconductor Wannier-Stark ladder due to the dynamic Fano resonance

“…To the best of our knowledge, there have been no studies on this issue except for Ref. [21]. According to some existing theoretical studies based on the lowest two-miniband tight-binding model [25,26], even if the strength of the THz wave (F ac ) increases, miniband collapse is still observed, although ac-Zener tunneling (ac-ZT) across photon sidebands (PSBs) corresponding to different minibands becomes more significant, and this results in pronounced anticrossings.…”

“…In addition to semiconductor systems, DL has also been extensively studied from the viewpoint of driven quantum tunneling and coherent control in systems such as optical SLs [16], atomic hyperfine and Zeeman-level structures [17][18][19], spin systems [20], and quantum chaos [21]. Further the concept of DL has recently been extended to trapped atoms in BoseEinstein condensates [22], Cooper pairs in Josephson qubits [23], and correlated electron systems [24].…”

“…First, in Ref. [21], the MCS problem of a fractional DWSL for modeled optical SLs, and not for semiconductor SLs, was analyzed by means of the Floquet-Bloch method. Quasienergy resonance structures were examined by solving the associated non-Hermitian eigenvalue problem with the Siegert boundary conditions, unlike in the present RFT method.…”

Phonon resonances in atomic currents through Bose-Fermi mixtures in optical lattices

“…The fermions confined to the tilted potential are represented by the eigenstates of the fermionic part ofĤ bf , i.e., the Wannier-Stark states [29,30]. The unitary transformation that relates the Wannier operatorsĉ j to the Wannier-Stark operatorsd j is given bŷ…”

“…The spectrum ofĤ ws constitutes a so-called WannierStark ladder [29,30] with a constant energy separation ∆ between adjacent sites, shown in Fig. 1.…”