| 1. |
- Tzalenchuk, Alexander, et al.
(författare)
-
Engineering and metrology of epitaxial graphene
- 2011
-
Ingår i: Solid State Communications. - : Elsevier. - 0038-1098 .- 1879-2766. ; 151:16, s. 1094-1099
-
Tidskriftsartikel (refereegranskat)abstract
- ere we review the concepts and technologies, in particular photochemical gating, which contributed to the recent progress in quantum Hall resistance metrology based on large scale epitaxial graphene on silicon carbide.
|
|
| 2. |
- Chua, C., et al.
(författare)
-
Quantum Hall Effect and Quantum Point Contact in Bilayer-Patched Epitaxial Graphene
- 2014
-
Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6992 .- 1530-6984. ; 14:6, s. 3369-3373
-
Tidskriftsartikel (refereegranskat)abstract
- We study an epitaxial graphene monolayer with bilayer inclusions via magnetotransport measurements and scanning gate microscopy at low temperatures. We find that bilayer inclusions can be metallic or insulating depending on the initial and gated carrier density. The metallic bilayers act as equipotential shorts for edge currents, while closely spaced insulating bilayers guide the flow of electrons in the monolayer constriction, which was locally gated using a scanning gate probe.
|
|
| 3. |
- Janssen, Tjbm, et al.
(författare)
-
Anomalously strong pinning of the filling factor nu=2 in epitaxial graphene
- 2011
-
Ingår i: Physical Review B - Condensed Matter and Materials Physics. - : American Physical Society. - 2469-9950 .- 2469-9969. ; 83:23, s. 233402-
-
Tidskriftsartikel (refereegranskat)abstract
- We explore the robust quantization of the Hall resistance in epitaxial graphene grown on Si-terminated SiC. Uniquely to this system, the dominance of quantum over classical capacitance in the charge transfer between the substrate and graphene is such that Landau levels (in particular, the one at exactly zero energy) remain completely filled over an extraordinarily broad range of magnetic fields. One important implication of this pinning of the filling factor is that the system can sustain a very high nondissipative current. This makes epitaxial graphene ideally suited for quantum resistance metrology, and we have achieved a precision of 3 parts in 1010 in the Hall resistance-quantization measurements.
|
|
| 4. |
- Janssen, Tjbm, et al.
(författare)
-
Breakdown of the quantum Hall effect in graphene
- 2012
-
Ingår i: CPEM Digest (Conference on Precision Electromagnetic Measurements). - 0589-1485. - 9781467304399 ; , s. 510-511
-
Konferensbidrag (refereegranskat)abstract
- We present experimental details on the carrier density dependent breakdown current in epitaxial graphene grown on SiC. We show that in this system even at very low carrier densities and moderate temperatures it is still possible to have a breakdown current large enough for metrologically accurate quantum Hall resistance measurements. This work paves the way for a simple bench top/turnkey quantum resistance standard.
|
|
| 5. |
- Kopylov, S., et al.
(författare)
-
Charge transfer between epitaxial graphene and silicon carbide
- 2010
-
Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 97:11
-
Tidskriftsartikel (refereegranskat)abstract
- We analyze doping of graphene grown on SiC in two models which differ by the source of charge transferred to graphene, namely, from SiC surface and from bulk donors. For each of the two models, we find the maximum electron density induced in monolayer and bilayer graphene, which is determined by the difference between the work function for electrons in pristine graphene and donor states on/in SiC, and analyze the responsivity of graphene to the density variation by means of electrostatic gates.
|
|
| 6. |
- Tzalenchuk, A.Y., et al.
(författare)
-
Graphene and the universality of the quantum Hall effect
- 2013
-
Ingår i: Proceedings of the International School of Physics "Enrico Fermi". - 1879-8195 .- 0074-784X. - 9781614993254 ; 185, s. 323-350
-
Konferensbidrag (refereegranskat)abstract
- The quantum Hall effect allows the standard for resistance to be defined in terms of the elementary charge and Planck's constant alone. The effect comprises the quantization of the Hall resistance in two-dimensional electron systems in rational fractions of RK=h/e2=25812.8074434(84) Ω (Mohr P. J. et al., Rev. Mod. Phys., 84 (2012) 1527), the resistance quantum. Despite 30 years of research into the quantum Hall effect, the level of precision necessary for metrology, a few parts per billion, has been achieved only in silicon and III-V heterostructure devices. In this lecture we show that graphene - a single layer of carbon atoms - beats these well-established semiconductor materials as the system of choice for the realisation of the quantum resistance standard. Here we shall briefly describe graphene technology, discuss the structure and electronic properties of graphene, including the unconventional quantum Hall effect and then present in detail the route, which led to the most precise quantum Hall resistance universality test ever performed. © Società Italiana di Fisica.
|
|
