Excitonic fine structure, light-hole excitons, and elongated nanostructures

This page gathers publications on excitonic fine structure, polarization, dark excitons, light-hole physics, and elongated nanostructures such as quantum dashes.

Electric-field control of exciton fine structure in alloyed nanowire quantum dot molecules

Phys. Rev. B 104, 195411 (2021)

This work extends electric-field control of exciton fine structure to alloyed nanowire quantum-dot molecules, where alloy randomness itself becomes part of the physics. It shows that nominally identical structures can exhibit qualitatively different field evolution of excitonic spectra.

Keywords: nanowire quantum dots, quantum dot molecules, fine-structure splitting

Main result: alloy randomness can both generate and reshape fine-structure splitting in nanowire quantum-dot molecules under electric field. Yet selected realizations still allow sub-µeV splitting without losing optical activity.

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Fine structure of dark and bright excitons in vertical electric fields: Atomistic theory of alloyed self-assembled InGaAs quantum dots

Phys. Rev. B 102, 245423 (2020)

This work analyzes excitonic fine structure and related optical anisotropies with atomistic many-body theory. It focuses on how realistic geometry, composition, and symmetry breaking determine the low-energy excitonic manifold.

Keywords: self-assembled quantum dots, fine-structure splitting

Main result: fine details of excitonic splitting and polarization are controlled by atomistic symmetry, realistic shape, and material inhomogeneity. Simplified continuum expectations are often insufficient at the µeV scale.

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Vanishing fine structure splitting in highly asymmetric InAs/InP quantum dots without wetting layer

Vanishing fine structure splitting in highly asymmetric InAs/InP quantum dots without wetting layer (2020)

This work uses atomistic modeling to explain why highly asymmetric InAs/InP quantum dots can nevertheless exhibit very small fine-structure splitting. It shows that realistic elongation, faceting, and atomistic symmetry can reshape the bright-exciton doublet in ways that differ from simple continuum expectations.

Keywords: InAs/InP, fine-structure splitting

Main result: atomistic symmetry and realistic geometry strongly control excitonic splitting and polarization. In particular, shape elongation of quantum dots can not only decrease, but even reverse, the splitting of the two lowest optically active excitonic states.

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Electric field tuning of excitonic fine-structure splitting in asymmetric InAs/InP nanowire quantum dot molecules

Phys. Rev. B 100, 235417 (2019)

This work shows how electric field can be used to tune excitonic fine-structure splitting in coupled InAs/InP nanowire quantum dots. It identifies a regime where bright-exciton splitting can be reduced without simultaneously suppressing optical activity.

Keywords: nanowire quantum dots, InAs/InP, quantum dot molecules

Main result: strong interdot coupling enables electric-field tuning of bright-exciton splitting down to zero while preserving useful optical strength. This makes nanowire quantum-dot molecules attractive for entangled-photon applications.

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From quantum dots to quantum dashes: Excitonic spectra of highly elongated InAs/InP nanostructures

Phys. Rev. B 99, 205402 (2019)

This publication contributes to atomistic theory of semiconductor nanostructures and their electronic or optical properties. It emphasizes realistic material, structural, or many-body effects beyond simplified textbook models.

Keywords: InAs/InP

Main result: realistic atomistic modeling is necessary to capture key electronic or optical features of these nanostructures.

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Spectra of dark and bright excitons in alloyed nanowire quantum dots

Phys. Rev. B 100, 045309 (2019)

This work analyzes how alloy randomness modifies both dark and bright excitons in nanowire quantum dots. It highlights that nominally weak atomistic disorder can strongly affect fine details of excitonic spectra and polarization properties.

Keywords: nanowire quantum dots

Main result: alloy randomness has a pronounced impact on the energies and optical signatures of both bright and dark excitons in nanowire quantum dots. Realistic alloy modeling is therefore essential for quantitative spectroscopy.

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Atomistic theory of excitonic fine structure in InAs/InP nanowire quantum dot molecules

Phys. Rev. B 95, 125407 (2017)

This work develops an atomistic description of excitonic fine structure in coupled InAs/InP nanowire quantum dots. It shows how interdot coupling and realistic atomistic asymmetry together govern the bright-exciton doublet and polarization response.

Keywords: nanowire quantum dots, InAs/InP, quantum dot molecules, fine-structure splitting

Main result: excitonic fine structure in nanowire quantum-dot molecules is controlled jointly by coupling and atomistic symmetry breaking. A simple single-dot picture is insufficient once realistic molecular coupling is present.

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Excitonic fine structure and binding energies of excitonic complexes in single InAs quantum dashes

Phys. Rev. B 94, 115434 (2016)

This publication contributes to atomistic theory of semiconductor nanostructures and their electronic or optical properties. It emphasizes realistic material, structural, or many-body effects beyond simplified textbook models.

Keywords: atomistic theory, quantum dots

Main result: realistic atomistic modeling is necessary to capture key electronic or optical features of these nanostructures.

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Excitonic fine structure of elongated InAs/InP quantum dots

Phys. Rev. B 88, 155319 (2013)

This work analyzes excitonic fine structure and related optical anisotropies with atomistic many-body theory. It focuses on how realistic geometry, composition, and symmetry breaking determine the low-energy excitonic manifold.

Keywords: InAs/InP, fine-structure splitting

Main result: fine details of excitonic splitting and polarization are controlled by atomistic symmetry, realistic shape, and material inhomogeneity. Simplified continuum expectations are often insufficient at the µeV scale.

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Fine structure of light-hole excitons in nanowire quantum dots

Phys. Rev. B 88, 115424 (2013)

This work analyzes the fine structure of light-hole excitons in nanowire quantum dots, going beyond the standard heavy-hole picture. It clarifies how confinement geometry can qualitatively alter polarization properties and the ordering of low-energy excitonic states.

Keywords: nanowire quantum dots, fine-structure splitting, light-hole excitons

Main result: sufficiently tall nanowire quantum dots can host a light-hole excitonic ground state with optical signatures distinct from conventional heavy-hole dots. The resulting fine structure is highly sensitive to realistic atomistic confinement.

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Influence of substrate orientation on exciton fine structure splitting of InAs/InP nanowire quantum dots

Nanoscale Res. Lett. 7, 265 (2012)

This work analyzes excitonic fine structure and related optical anisotropies with atomistic many-body theory. It focuses on how realistic geometry, composition, and symmetry breaking determine the low-energy excitonic manifold.

Keywords: nanowire quantum dots, InAs/InP, fine-structure splitting

Main result: fine details of excitonic splitting and polarization are controlled by atomistic symmetry, realistic shape, and material inhomogeneity. Simplified continuum expectations are often insufficient at the µeV scale.

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