Probing the quantum states of self-assembled InAs dots by magnetotunneling spectroscopy

Patanè, A.; Hill, R.; Eaves, L.; Main, P. C.; Henini, M.; Zambrano, M. L.; Levin, A. D.; Mori, Nobuya; Hamaguchi, Chihiro; Dubrovskiĭ, Yu. V.; Вдовин, Е. Е.; Austing, D. G.; Tarucha, Seigo; Hill, G.

doi:10.1103/physrevb.65.165308

Phys. Rev. B

2002

DOI: 10.1103/physrevb.65.165308

|View full text |Cite

Probing the quantum states of self-assembled InAs dots by magnetotunneling spectroscopy

A. Patanè

R. Hill

L. Eaves

et al.

Help me understand this report

Search citation statements

Order By: Relevance

Paper Sections

Select...

Citation Types

Supporting

Mentioning

Contrasting

Year Published

2003

2019

Publication Types

Select...

Article6

Relationship

Self Cite1

Independent5

Authors

Journals

Cited by 87 publications

(69 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This indicates that the wave function has a typical spatial extent ͑full width at half maximum͒ along x-y of 10 nm. 9 Consistent with the Gaussian shape of the wave function along x-y, the lack of any peak splitting with increasing B z indicates the absence of an orbital Zeeman effect and that the localized states have orbital angular momentum component ͗ᐉ z ͘ =0.…”

mentioning

confidence: 62%

“…8,9,17,18 We attribute this to the fact that the energy levels of the QD ground states lie below the chemical potential in the emitter at all biases so energy-conserving tunneling transitions through the dots are not allowed.…”

mentioning

confidence: 99%

“…For example, the current in the QD sample is approximately one order of magnitude lower than in the C sample. 9 This is attributed to the fact that most of the electrons that tunnel into the QW relax down to the lower energy states of the QDs. They then tunnel into the collector through the second barrier which has a relatively large height and low transmission coefficient.…”

mentioning

confidence: 99%

“…20 Also for tunneling into localized states in the QW, the dependence of the amplitude of the resonant peaks on B xy provides a powerful means for imaging the electron wave function. 8,9 Figure 3͑a͒ shows the effect on the I͑V͒ curves of B xy . With increasing B xy , the weak shoulder associated with electron tunneling into the wetting layer subband E 1 develops into a well-defined resonant peak, as has been reported in earlier experiments on RTDs incorporating QDs.…”

mentioning

confidence: 99%

“…This leads to a spectrum of discrete energy levels, similar to that of atoms. [1][2][3][4][5][6][7] The analogy with atoms is strengthened by the observation of excitonic and electronic states with s-, p-, and d-like character, all of which have been observed in optical 6 and tunneling 8,9 spectroscopy studies. In addition, optical pumping experiments have provided evidence for shell-like filling of the electronic orbitals.…”

mentioning

confidence: 99%

See 4 more Smart Citations

Excited states of ring-shaped (InGa)As quantum dots in aGaAs∕(AlGa)Asquantum well

et al. 2005

Self Cite

View full text Add to dashboard Cite

By studying the resonant tunneling of electrons through self-assembled ring-shaped ͑InGa͒As quantum dots embedded in the quantum well of an ͑AlGa͒As/ GaAs/ ͑AlGa͒As heterostructure, we find evidence for the existence of excited states of the quantum dots which exhibit a 2p z -like character along the growth direction z. The states are investigated by magnetotunneling spectroscopy with magnetic fields applied parallel and perpendicular to z. DOI: 10.1103/PhysRevB.72.085309 PACS number͑s͒: 73.23.Ϫb, 73.63.Kv, 73.40.Gk In self-assembled semiconductor quantum dots ͑QDs͒, carriers are confined in all three spatial dimensions. This leads to a spectrum of discrete energy levels, similar to that of atoms. [1][2][3][4][5][6][7] The analogy with atoms is strengthened by the observation of excitonic and electronic states with s-, p-, and d-like character, all of which have been observed in optical 6 and tunneling 8,9 spectroscopy studies. In addition, optical pumping experiments have provided evidence for shell-like filling of the electronic orbitals. 6 However, in contrast to a real atom, a QD has a highly anisotropic confining potential, since its dimensions in the plane of growth ͑the wetting layer plane x-y͒ are typically an order of magnitude larger than that along the growth direction ͑z͒. Hence spectroscopic investigations have been restricted mainly to states for which the excitations are confined to the x-y plane.In this paper, we study the electronic properties of QDs with an unusual ring-shape morphology, which can be generated under special growth conditions. We report experimental evidence for the presence of excited QD states with a 2p z -like character. States with 2p z character have been observed previously for Si donors in a GaAs QW.10 For this study we use resonant tunneling heterostructure diodes in which a single layer of self-assembled ͑InGa͒As quantum dots is embedded in an ͑AlGa͒As/ GaAs/ ͑AlGa͒As quantum well. The 2p z -like quasibound states are revealed by the presence of additional resonant peaks in the tunnel current. By combining photoluminescence and magnetotunneling spectroscopy with magnetic field B applied along z and in the x-y plane, we show that these resonances correspond to electron tunneling into 2p z -like states with binding energies in the range 5 -30 meV below the edge of the continuum of the first excited two-dimensional ͑2D͒ subband of the GaAs QW.Despite the ring-shape structure of the dots, we find no evidence in our tunneling data for states showing AharonovBohm character.Our device is a GaAs/ Al 0.4 Ga 0.6 As double barrier electron resonant tunneling diode ͑RTD͒ grown by molecular beam epitaxy ͑MBE͒ on a ͑100͒-oriented n + GaAs substrate. The conduction band profile of the device and the QD energy levels are shown schematically in Fig. 1͑a͒. Two 8-nm-thick Al 0.4 Ga 0.6 As tunnel barriers define a 10-nm-thick GaAs QW, which contains a layer of ͑InGa͒As QDs. Undoped GaAs spacer layers of width 50 nm separate the Al 0.4 Ga 0.6 As barriers from lightly n-doped ͑n =2ϫ 10 1...

show abstract

mentioning

confidence: 62%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Excited states of ring-shaped (InGa)As quantum dots in aGaAs∕(AlGa)Asquantum well

et al. 2005

Self Cite

View full text Add to dashboard Cite

show abstract

Messung von Orbitalen: Provokation oder Wirklichkeit?

Schwarz

2006

Angewandte Chemie

View full text Add to dashboard Cite

Können komplexe Orbitale real gemessen werden? Seit Jahren ist es in der Tat möglich, Orbitalfunktionen auf verschiedene Weisen aus Messdaten zu rekonstruieren. Seit kurzem geht das sogar mit Femtosekunden‐Messdaten, wenn auch auf einem geringeren Genauigkeitsniveau als mithilfe rein theoretischer Methoden. Das HOMO des N2‐Moleküls wurde mittels Computeralgorithmen direkt aus experimentellen laserspektroskopischen Interferenz‐Intensitätsdaten rekonstruiert (siehe Bild).

show abstract

Measuring Orbitals: Provocation or Reality?

Schwarz

2006

Angew Chem Int Ed

View full text Add to dashboard Cite

Can complex orbitals really be measured? Orbital functions can indeed be reconstructed from measured data by various approaches. Now even femtosecond measurements can be used, though the results are still less accurate than those achieved with purely theoretical methods. The HOMO of the N2 molecule (see picture) has been reconstructed directly from experimental laser‐spectroscopic interference intensity measurements by means of computer algorithms.

show abstract

scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.

Contact Info

customersupport@researchsolutions.com

10624 S. Eastern Ave., Ste. A-614

Henderson, NV 89052, USA

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Blog Terms and Conditions API Terms Privacy Policy Contact Cookie Preferences Do Not Sell or Share My Personal Information

Made with 💙 for researchers

Part of the Research Solutions Family.

Probing the quantum states of self-assembled InAs dots by magnetotunneling spectroscopy

Cited by 87 publications

References 50 publications

Excited states of ring-shaped (InGa)As quantum dots in aGaAs∕(AlGa)Asquantum well

Excited states of ring-shaped (InGa)As quantum dots in aGaAs∕(AlGa)Asquantum well

Messung von Orbitalen: Provokation oder Wirklichkeit?

Measuring Orbitals: Provocation or Reality?

Contact Info

Product

Resources

About