Title :

Formation of quantum dots in the potential fluctuations of InGaAs heterostructures probed by scanning gate microscopy

Author(s) :

Liu, Peng [Auteur]
Nano-Electronique Quantique et Spectroscopie [NEEL - QuNES]
Martins, Frederico [Auteur]
Institut de la matière condensée et des nanosciences / Institute of Condensed Matter and Nanosciences [IMCN]
Hackens, Benoit [Auteur]
Institut de la matière condensée et des nanosciences / Institute of Condensed Matter and Nanosciences [IMCN]
Desplanque, Ludovic [Auteur]
Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 [IEMN]
Wallart, Xavier [Auteur]
Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 [IEMN]
Pala, Marco [Auteur]
Institut de Microélectronique, Electromagnétisme et Photonique - Laboratoire d'Hyperfréquences et Caractérisation [IMEP-LAHC]
Huant, Serge [Auteur]
Nano-Optique et Forces [NEEL - NOF]
Bayot, Vincent [Auteur]
Institut de la matière condensée et des nanosciences / Institute of Condensed Matter and Nanosciences [IMCN]
Nano-Optique et Forces [NEEL - NOF]
Sellier, Hermann [Auteur correspondant]
Nano-Electronique Quantique et Spectroscopie [NEEL - QuNES]

Journal title :

Physical Review B: Condensed Matter and Materials Physics (1998-2015)

Pages :

075313

Publisher :

American Physical Society

Publication date :

2015-02-25

ISSN :

1098-0121

HAL domain(s) :

Physique [physics]/Matière Condensée [cond-mat]/Systèmes mésoscopiques et effet Hall quantique [cond-mat.mes-hall]

English abstract : [en]

The disordered potential landscape in an InGaAs/InAlAs two-dimensional electron gas patterned into narrow wires is investigated by means of scanning gate microscopy. It is found that scanning a negatively charged tip above ...
Show more >The disordered potential landscape in an InGaAs/InAlAs two-dimensional electron gas patterned into narrow wires is investigated by means of scanning gate microscopy. It is found that scanning a negatively charged tip above particular sites of the wires produces conductance oscillations that are periodic in the tip voltage. These oscillations take the shape of concentric circles whose number and diameter increase for more negative tip voltages until full depletion occurs in the probed region. These observations cannot be explained by charging events in material traps, but are consistent with Coulomb blockade in quantum dots forming when the potential fluctuations are raised locally at the Fermi level by the gating action of the tip. This interpretation is supported by simple electrostatic simulations in the case of a disorder potential induced by ionized dopants. This work represents a local investigation of the mechanisms responsible for the disorder-induced metal-to-insulator transition observed in macroscopic two-dimensional electron systems at low enough density.Show less >

Language :

Anglais

Peer reviewed article :

Oui

Audience :

Internationale

Popular science :

Non

Collections :

• Institut d'Électronique, de Microélectronique et de Nanotechnologie (IEMN) - UMR 8520

Source :

Harvested from HAL