Fabrication of quantum-dot devices in graphene

Moriyama, Satoshi; Morita, Yoshifumi; Watanabe, Eiichiro; Tsuya, Daiju; Uji, Shinya; Shimizu, Masaru; Ishibashi, Koji

doi:10.1088/1468-6996/11/5/054601

Cited by 17 publications

(15 citation statements)

References 32 publications

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“…Most experiments showed one or several Coulomb diamonds closing at zero bias 40,45,61,234,240,241,[243][244][245][246][247][248][249]251,252,256,258,260,263,267,268,271,[276][277][278] and in a few experiments, diamonds did not close. 242,274,275,279 For the double dot experiments, the expected hexagon patterns were observed 221,250,[253][254][255]257,261,262,264,269,270,272,273 and various references report the observation of finite bias triangles. 250,[253][254][255]261,264,…”

Section: A More Regular Coulomb Blockade Than In Nanoribbonsmentioning

confidence: 93%

“…The majority of devices were fabricated by connecting graphene islands with narrow constrictions to graphene leads. 40,221,[242][243][244][245][246][247][248][249][250][251][252][254][255][256][257][258][259][260][261][262][263][264][265][266][267][268][269][270][271][272][273][276][277][278] Various designs also used gated regions: top gates on a single layer ribbon 253 and split gates on bilayer graphene. 61,234,274 Other designs used a single constriction as a quantum dot 240,241,275 or high resistive contacts.…”

Section: A Device Geometriesmentioning

confidence: 99%

“…279 Patterns were designed with the aim of fabricating single 40,61,234,[240][241][242][243][244][245][246][247][248][249]251,252,[258][259][260]263,[265][266][267][268]271,[274][275][276][277][278][279] or serial double quantum dots. 221,250,[253][254][255]257,261,262,264,267,269,270,272,273 Further, more exotic devices with three leads 45,265 or parallel double quantum dots 257,262 were fabricated.…”

Section: A Device Geometriesmentioning

confidence: 99%

“…251,256,and 271) or multiple (see Refs. 40,45,61,221,234,[242][243][244][245][246][247][248][249][250]252,254,255,[257][258][259][260][261][262][263][264][265][266][267][268][269][270]272,273,276, and 278) side gates. Side gates were fabricated with graphene except in one experiment where metal side gates were used.…”

Section: A Device Geometriesmentioning

confidence: 99%

“…Often, it was found that the coupling between a dot and another dot or a lead changed non-monotonically with applied gate voltage. 245,247,250,253,254,258,259,261,262,264,270,276 Multiple experiments found "transmission resonances" 45,242,[245][246][247]254,[258][259][260][261]265,268 originating from the constrictions. Most of them were identified by measuring transport as a function of multiple gates.…”

Section: B Influence Of Constrictionsmentioning

confidence: 99%

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Localized charge carriers in graphene nanodevices

Bischoff

Varlet

Simonet

et al. 2015

Applied Physics Reviews

100

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Graphene—two-dimensional carbon—is a material with unique mechanical, optical, chemical, and electronic properties. Its use in a wide range of applications was therefore suggested. From an electronic point of view, nanostructured graphene is of great interest due to the potential opening of a band gap, applications in quantum devices, and investigations of physical phenomena. Narrow graphene stripes called “nanoribbons” show clearly different electronical transport properties than micron-sized graphene devices. The conductivity is generally reduced and around the charge neutrality point, the conductance is nearly completely suppressed. While various mechanisms can lead to this observed suppression of conductance, disordered edges resulting in localized charge carriers are likely the main cause in a large number of experiments. Localized charge carriers manifest themselves in transport experiments by the appearance of Coulomb blockade diamonds. This review focuses on the mechanisms responsible for this charge localization, on interpreting the transport details, and on discussing the consequences for physics and applications. Effects such as multiple coupled sites of localized charge, cotunneling processes, and excited states are discussed. Also, different geometries of quantum devices are compared. Finally, an outlook is provided, where open questions are addressed.

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Section: A More Regular Coulomb Blockade Than In Nanoribbonsmentioning

confidence: 93%

Section: A Device Geometriesmentioning

confidence: 99%

Section: A Device Geometriesmentioning

confidence: 99%

Section: A Device Geometriesmentioning

confidence: 99%

Section: B Influence Of Constrictionsmentioning

confidence: 99%

See 3 more Smart Citations

Localized charge carriers in graphene nanodevices

Bischoff

Varlet

Simonet

et al. 2015

Applied Physics Reviews

100

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Magnetic polaron formation in graphene-based single-electron transistor

Savin

Kuivalainen

Новиков

et al. 2014

Phys. Status Solidi B

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We theoretically study the magnetic polaron (MP) formation in a ferromagnetic graphene single-electron transistor (SET), which consists of a graphene quantum dot (QD) between two insulating layers, i.e., a ferromagnetic insulator EuO and a nonmagnetic substrate such as SiC. In the lateral direction the QD is electrically coupled to source, drain and gate electrodes, so that the number of electrons can be controlled by the gate voltage. Due to a proximity effect at the EuO/graphene interface, i.e., the exchange interaction between the charge carriers in graphene and the localized magnetic electrons in EuO, there is a magnetic coupling between the graphene QD and EuO. Using Green's function technique an expression for the total free energy of the SET is derived, which then is minimized at the given temperature and gate voltage. This leads to the MP formation and a consequent local enhancement of the ferromagnetic properties of EuO at the EuO/graphene interface. The MP formation is enforced by the large Coulomb interaction between the carriers in graphene. The spin polarization at the graphene/EuO interface in the QD area can be controlled by the gate voltage of the SET.

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Controllable functionalization and wettability transition of graphene-based films by an atomic oxygen strategy

Zhang

Shen

et al. 2013

J Nanopart Res

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Though chemical modification of graphene based on Hummers method has been most widely used to tailor its properties and interfacial characteristics, a method which could achieve definitive and controllable groups and properties is still highly required. Here, we demonstrate a high-vacuum oxidation strategy by atomic oxygen (AO) and investigate the AO induced functionalization and wettability transition in films made from basal-defect- and oxide-free graphene dispersions. These graphene-based films are neither graphene nor graphite, but graphene blocks constituted by numerous randomly stacked graphene flakes. It is found that AO induced functionalization of these films through the formation of epoxy groups, sp3 configuration, ether, and double and triple C–O groups. The films turn to be hydrophilic after exposed to AO. The contact angle increases with AO exposure time. This phenomenon is attributed to the lower surface roughness induced by collision and/or edge erosion of energetic ions to the film surface and is further explained by the Wenzel model. The demonstrated strategy can overcome limitations of Hummers method, provide possibility to gain functionalization and wettability transition in liquid-phase exfoliated basal-defect- and oxide-free graphene in the dry environment, and may extend the study and application of this material in spacecraft in low earth orbit.

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Fabrication of quantum-dot devices in graphene

Cited by 17 publications

References 32 publications

Localized charge carriers in graphene nanodevices

Localized charge carriers in graphene nanodevices

Magnetic polaron formation in graphene-based single-electron transistor

Controllable functionalization and wettability transition of graphene-based films by an atomic oxygen strategy

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