Consequences of Low Symmetry in Quantum Wires: Exciton Degeneracies and Quasi-Equilibrium High-Density Regime

Dupertuis, M.‐A.

doi:10.1002/1521-3951(200009)221:1<323::aid-pssb323>3.0.co;2-5

Cited by 5 publications

(5 citation statements)

References 4 publications

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“…In general, the Coulomb interaction will lift the degeneracies between different types of excitons, leading to a polarization-dependent fine structure. When spin splitting is ignored in the conduction band, it can be shown further [21] that the A and A excitons are degenerate in C 1 symmetry, as well as the A 1 and B 1 (A 2 and B 2 , respectively) in C s symmetry. Even though such fine structures are hidden in present PLE spectra by inhomogenous broadening, more sophisticated experimental techniques are available to unravel it.…”

Section: Qwr Symmetrymentioning

confidence: 99%

The impact of low symmetry on the electronic and optical properties of quantum wires

et al. 2000

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The role of the confinement potential symmetry on the electronic and optical properties of quantum wires is systematically studied. In a wide class of quantum wires with mirror symmetry we evidence a new set of optical transitions resulting both from band mixing and C2v symmetry breaking at zone center. Several kinds of quasi-one-dimensional excitons are predicted as well as their specific dipole coupling. Even for ultralow C1 symmetry we find independent excitons with distinct polarization selection rules.

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Section: Qwr Symmetrymentioning

confidence: 99%

The impact of low symmetry on the electronic and optical properties of quantum wires

et al. 2000

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“…Let us give here an intuitive justification for this extensive effort. We shall first discuss the effects of a single symmetry plane, already quite well-known (see [10], and subsequent works [11,[34][35][36]). Then we shall enlighten in detail the difficulties involved in applying these results, based on rather elementary concepts, to higher symmetries.…”

Section: B the Effects Of Symmetry On The Envelope Functionsmentioning

confidence: 99%

“…T-and V-shaped quantum wires [8,9]) is already well developed [10] and has lead to fundamental conclusions regarding their electronic and optical properties. First electronic and excitonic states can be labelled with respect to their characteristic transformation properties under symmetry operations, second rigorous and important selection rules were readily obtained on the basis of such a classification, useful even in a low symmetry case [10,11]. The effects of lateral confinement to the polarization anisotropy were largely studied [12][13][14][15][16].…”

mentioning

confidence: 99%

Maximal symmetrization and reduction of fields: Application to wave functions in solid-state nanostructures

Dalessi¹,

Dupertuis²

2010

Phys. Rev. B

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A general formalism for the maximal symmetrization and reduction of fields ͑MSRFs͒ is proposed and applied to wave functions in solid-state nanostructures. Its primary target is to provide an essential tool for the study and analysis of the electronic and optical properties of semiconductor quantum heterostructures with relatively high point-group symmetry and studied with the k · p formalism. Nevertheless the approach is valid in a much larger framework than k · p theory; it is applicable to arbitrary systems of coupled partial differential equations ͑e.g., strain equations or Maxwell equations͒. This general MSRF formalism makes extensive use of group theory at all levels of analysis. For spinless problems ͑scalar equations͒, one can use a systematic spatial domain reduction ͑SDR͒ technique which allows, for every irreducible representation, to reduce the set of equations on a minimal domain with automatic incorporation of the boundary conditions at the border, which are shown to be nontrivial in general. For a vectorial or spinorial set of functions, the SDR technique must be completed by the use of an optimal basis in vectorial or spinorial space ͑in a crystal we call it the optimal Bloch function basis͒. The full MSR formalism thus consists of three steps: ͑1͒ explicitly separate spatial ͑or Fourier space͒ and vectorial ͑spinorial͒ part of the operators and eigenstates, ͑2͒ choose, according to the symmetry and well defined prescriptions ͑e.g., specific transformation properties͒, optimal fully symmetrized basis for both spatial and vector ͑or spin͒ space, and ͑3͒ finally apply the SDR to every individual scalar ultimate component function. We show that with such a formalism the coupling between different vectorial ͑spinorial͒ components by symmetry operations becomes minimized and every ultimately reduced envelope function acquires a welldefined specific symmetry. The advantages are numerous: sharper insights on the symmetry properties of every eigenstate, minimal coupling schemes ͑analytically and computationally exploitable at the component function level͒, and minimal computing domains. The formalism can be applied also as a postprocessing operation, offering all subsequent analytical and computational advantages of symmetrization. The specific case of a quantum wire with C 3v point group symmetry is used as a concrete illustration of the application of MSRF.

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“…For group theory notations we follow Refs. [1] and [2] based on [7]. We renounce to use the notations of the well-known Koster et al tables (MIT Press, 1963) because they are much less complete, systematic and practical.…”

Section: Two Conflicting Arguments For Z-like Quantum Wiresmentioning

confidence: 99%

“…The symmetry of the lateral profile of quantum wires (QWR), as well as time-reversal (TR) symmetry, provide stringent conditions for the band structure of quantum wires with well-defined selection rules [1,2]. In this paper we shall concentrate on one of the remaining low-symmetry case: Z-like QWRs.…”

Section: Introductionmentioning

confidence: 99%

The Band Structure of Z-like Quantum Wires

Dupertuis

Marti

Michelini

2002

phys. stat. sol. (b)

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We analyze the electronic properties of quantum wires with a Z-like profile within four-band models for the valence band of a semiconductor of diamond and zinc blende type. Group-theoretical considerations show that the valence-band structure is doubly degenerate only when the linear kterms (coming e.g. from the bulk crystal inversion asymmetry) are neglected. The considerations apply to the more general case of a profile containing a 2D center of inversion.

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Consequences of Low Symmetry in Quantum Wires: Exciton Degeneracies and Quasi-Equilibrium High-Density Regime

Cited by 5 publications

References 4 publications

The impact of low symmetry on the electronic and optical properties of quantum wires

The impact of low symmetry on the electronic and optical properties of quantum wires

Maximal symmetrization and reduction of fields: Application to wave functions in solid-state nanostructures

The Band Structure of Z-like Quantum Wires

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