banner image
No data available.
Please log in to see this content.
You have no subscription access to this content.
No metrics data to plot.
The attempt to load metrics for this article has failed.
The attempt to plot a graph for these metrics has failed.
Charge detection in graphene quantum dots
Rent this article for
View: Figures


Image of FIG. 1.
FIG. 1.

Nanostructured graphene QD device with nanoribbon and characteristic transport measurements. (a) Scanning force micrograph of the measured device. The central island is connected to source and drain contacts by two constrictions. The diameter of the dot is 200 nm and the constrictions are 35 nm wide. The graphene nanoribbon acts as CD. Three lateral gates B1, B2, and PG are used to tune the devices. (b) BG characteristics of the QD device (upper panel) and the CD (lower panel) shown in (a). Both measurements were performed at a source-drain (bias) voltage of and at 1.7 K. The inset shows Coulomb blockade resonances observed inside the transport gap as a function of the BG voltage over a range of 150 mV. (c) Coulomb blockade diamonds in differential conductance (logarithmic scale) recorded as function of the PG and bias voltage with fixed BG voltage . The charging energy is estimated to be .

Image of FIG. 2.
FIG. 2.

(a) Dot conductance and (b) CD conductance as a function of PG voltage for a fixed BG voltage . (a) The arrows indicate Coulomb blockade resonances that can be hardly measured by conventional means because the current levels are too low. (b) However, they can be detected by the CD. Bias on dot: . Bias on CD: .

Image of FIG. 3.
FIG. 3.

(a) Conductance of the QD as a function of PG voltage and BG voltage . The BG voltage is converted to a relative scale starting at with . For this measurement a source-drain bias of is symmetrically applied. Narrowly spaced periodic lines are Coulomb blockade resonances (black line with long dashes), while the larger scale features are attributed to a modulation of the transmission through the barriers (white dotted line). (b) Simultaneous measurement of the CD conductance . The broad line with increased conductance is less affected by changing the PG voltage compared to the Coulomb blockade resonances in the dot, and it is attributed to a local resonance in the CD (short dashed line). In addition to this broad line, faint lines with a slope corresponding to the Coulomb blockade resonances in the QD are observed (arrows). (c) Derivative of the CD conductance is plotted in (b) with respect to PG voltage , where the lines with short and long dashes indicate the two different lever arms.


Article metrics loading...


Full text loading...

This is a required field
Please enter a valid email address
752b84549af89a08dbdd7fdb8b9568b5 journal.articlezxybnytfddd
Scitation: Charge detection in graphene quantum dots