Electrostatic effects in coupled quantum dot-point contact-single electron transistor devices
Artikel i vetenskaplig tidskrift, 2012

We study the operation of a system where quantum dot (QD) and point contact (PC) defined in a two-dimensional electron gas of a high-mobility GaAs/AlGaAs heterostructure are capacitively coupled to each other and to metallic single electron transistor (SET). The charge state of the quantum dot can be probed by the point contact or single electron transistor. These can be used for sensitive detection of terahertz radiation. In this work, we explore an electrostatic model of the system. From the model, we determine the sensitivity of the point contact and the single electron transistor to the charge excitation of the quantum dot. Nearly periodic oscillations of the point contact conductance are observed in the vicinity of pinch-off voltage. They can be attributed to Coulomb blockade effect in a quasi-1D channel because of unintentional formation of small quantum dot. The latter can be a result of fluctuations in GaAs quantum well thickness.

conductance

coulomb-blockade

Författare

S. Pelling

Royal Holloway University of London

Ernst Otto

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantkomponentfysik

S. Spasov

Royal Holloway University of London

Sergey Kubatkin

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantkomponentfysik

R. Shaikhaidarov

Royal Holloway University of London

K. Ueda

University of Tokyo

S. Komiyama

University of Tokyo

V. N. Antonov

Royal Holloway University of London

Journal of Applied Physics

0021-8979 (ISSN) 1089-7550 (eISSN)

Vol. 112 1 014322

Ämneskategorier

Fysik

DOI

10.1063/1.4736419

Mer information

Senast uppdaterat

2018-02-28