Exciton Storage in a Nanoscale Aharonov-Bohm Ring with Electric Field Tuning

Fischer, Andrea M.; Campo, Vivaldo L.; Portnoi, M. E.; Römer, Rudolf A.

doi:10.1103/physrevlett.102.096405

Cited by 60 publications

(51 citation statements)

References 216 publications

(335 reference statements)

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“…An in-plane electric field could possibly increase the polarization of an exciton and hence, the visibility of this exciton AB effect. 18 The observation of such effect is not only of fundamental interest, Fischer et al 19,20 suggested recently that the exciton AB effect in a quantum ring can be dynamically controlled by a combination of magnetic and electric fields, a new proposal to trap light.…”

Section: Introductionmentioning

confidence: 99%

Gate controlled Aharonov-Bohm-type oscillations from single neutral excitons in quantum rings

Ding

Akopian

et al. 2010

Phys. Rev. B

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We report on a magnetophotoluminescence study of single self-assembled semiconductor nanorings which are fabricated by molecular-beam epitaxy combined with AsBr 3 in situ etching. Oscillations in the neutral exciton radiative recombination energy and in the emission intensity are observed under an applied magnetic field. Further, we control the period of the oscillations with a gate potential that modifies the exciton confinement. We infer from the experimental results, combined with calculations, that the exciton Aharonov-Bohm effect may account for the observed effects.

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Section: Introductionmentioning

confidence: 99%

Gate controlled Aharonov-Bohm-type oscillations from single neutral excitons in quantum rings

Ding

Akopian

et al. 2010

Phys. Rev. B

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“…The corresponding eigenfunctions can be determined exactly and the exciton energy obtained from a set of transcendental equations, as reported in Ref. 12.…”

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confidence: 99%

“…To formulate a consistent picture of correlation between AB interference and e − h interaction, we have used a simplified model according to which the two particle Hamiltonian of the e − h pair interacting by means of a contact potential in a ring of radius R and zero width threaded by a magnetic flux Φ = BπR 2 is described by [12] …”

mentioning

confidence: 99%

Aharonov-Bohm Interference in Neutral Excitons: Effects of Built-In Electric Fields

et al. 2010

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We report a comprehensive discussion of quantum interference effects due to the finite structure of excitons in quantum rings and their first experimental corroboration observed in the optical recombinations. Anomalous features that appear in the experiments are analyzed according to theoretical models that describe the modulation of the interference pattern by temperature and built-in electric fields.PACS numbers: 71.35.Ji, 73.21.La, 78.20.Ls, 78.67.Hc The nanoscale ring structures, or quantum rings (QRs), have attracted the interest of the scientific community due to their unique rotational symmetry and the possibility to verify quantum mechanical phenomena.[1, 2, 3] Among these, the study of Aharonov-Bohm (AB)-like effects has gained a significant impetus, [4,5,6] and these efforts have gone beyond the original discussion of the AB interpretation on the nature of electromagnetic potentials and their role in quantum mechanics. [7] It is reasonable to say that the study of coherent interference occurring in transport properties of nanoscopic QRs, as proposed in Ref. 7 encounters, at the moment, serious scale limitations which has encouraged the search for optical implications associated to AB-effects.These endeavors applied to nanoscopic QRs do not strictly meet the original conditions for the ABconfiguration since the carriers are confined within regions with finite values of magnetic field. However, we still consider an observed effect as of AB-type if it can be explained assuming that the magnetic field is ideally concentrated in the middle of the QRs, i. e., when such effect comes essentially from potential vector-mediated quantum interference. As also considered in Ref. 8, in stationary systems this interference is generally reflected in a boundary condition and it is not as explicit as in the famous picture of an AB scattering situation.In this work we consider AB-interference in excitonic states as proposed theoretically in Refs. 9, 10, 12. Instead of looking only at the oscillatory dependence on magnetic flux of the electron-hole (e − h) recombination energy during photo-luminescence (PL), we also consider the excitonic oscillator strength whose oscillatory behavior reflects directly the changes in the exciton wavefunction as the magnetic flux increases. A similar experimental work was reported in Ref. 6 for type-II QRs, however, here we study type-I systems where both electron and hole move in the ring so that the correlation between them is crucial to the oscillatory behavior found in the PL integrated intensity. The samples studied here were grown using a RIBER 32P solid-source molecular beam epitaxy chamber and the QRs were grown using the following procedure. A 0.5 µm GaAs buffer layer was grown on semi-insulating (100) GaAs substrates at 580• C, after oxide desorption. Then, it was followed by 2.2 ML of InAs and the formation of quantum dots (QDs) at 520• C. The dots were obtained using the Stranski-Krastanov growth mode. Cycles of 0.14 ML of InAs plus a 2 s interruption under As 2 flux were r...

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“…A short-range interaction between the electron and the hole has been investigated for one-dimensional (1D) rings, 13,14,18,19 where also the effect of an external electric field can be included. 20 Intermediate models assume twodimensional (2D) rings with narrow width under harmonic confinement and Coulomb-like interaction potentials between the electron and the hole, 21,22 or radial-polarized excitons when electrons and holes move in different circles. [23][24][25] The excitonic AB effect in 2D rings has been studied in models with harmonic 26 and geometric 15,27,28 confining potential or using a 2D attractive annular Hubbard model.…”

Section: Introductionmentioning

confidence: 99%

Excitonic Aharonov-Bohm effect in a two-dimensional quantum ring

2011

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We study theoretically the optical properties of an exciton in a two-dimensional ring threaded by a magnetic flux. We model the quantum ring by a confining potential that can be continuously tuned from strictly one-dimensional to truly two-dimensional with finite radius-to-width ratio. We present an analytic solution of the problem when the electron-hole interaction is short ranged. The oscillatory dependence of the oscillator strength as a function of the magnetic flux is attributed to the Aharonov-Bohm effect. The amplitude of the oscillations changes upon increasing the width of the quantum ring. We find that the Aharonov-Bohm oscillations of the ground state of the exciton decrease with increasing the width, but, remarkably, the amplitude remains finite down to radius-to-width ratios less than unity. We attribute this resilience of the excitonic oscillations to the nonsimple connectedness of our chosen confinement potential with its centrifugal core at the origin.

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Exciton Storage in a Nanoscale Aharonov-Bohm Ring with Electric Field Tuning

Cited by 60 publications

References 216 publications

Gate controlled Aharonov-Bohm-type oscillations from single neutral excitons in quantum rings

Gate controlled Aharonov-Bohm-type oscillations from single neutral excitons in quantum rings

Aharonov-Bohm Interference in Neutral Excitons: Effects of Built-In Electric Fields

Excitonic Aharonov-Bohm effect in a two-dimensional quantum ring

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