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Reference : UMR9001-REBRIB-005
Workplace : PALAISEAU,PALAISEAU
Date of publication : Thursday, October 15, 2020
Scientific Responsible name : Rebeca Ribeiro
Type of Contract : PhD Student contract / Thesis offer
Contract Period : 36 months
Start date of the thesis : 1 January 2021
Proportion of work : Full time
Remuneration : 2 135,00 € gross monthly
Description of the thesis topic
The first isolation of graphene, a thinlayer of one carbon atom arranged in hexagons, attracted a lot of attention in 2005 due to its remarkable characteristics: high mobility of the carriers, ambipolar behavior, high mechanical strength. Shortly afterwards, other 2D layered materials also proved to have remarkable characteristics and to host a large number of condensed matter physics phenomena. A great technological achievement today is the stacking of these 2D layers to form van der Waals (vdW) heterostructures [Nat. Nanotech 5, 722] and thus to combine the properties of each material to design materials with new properties [Nature 499, 419].
Unlike classical 2D materials grown by molecular beam epitaxy, layered vdW structures can be made of any combination of 2D materials, since there are no lattice parameter restrictions. The other degree of freedom of these heterostructures is the relative angular alignment between its layers, which can significantly alter its fundamental properties. A remarkable example of this, foreseen for some vdW heterostructures, is the emergence of phases of matter where the charge carriers flow without dissipation. In graphene heterostructures crystallographically aligned with boron nitride (graphene isomorphic insulator), such a phase has been predicted. However, due to the scarcity of experimental tools to control the alignment of the layers, the available observations remain inconclusive [Science 346, 448; Science adv. 4, eaaq0194].
During this PhD thesis, we propose to use a new technique to control the angular alignment between layers in a vdW heterostructure [Science 361, 690] to study the generation and control of electrical signals related to these phases of matter in graphene.
C2N is located on the Saclay plateau south of Paris. The work will be carried out within the PHYNANO group, specialized in physics and technology of nanostructures from fundamental to applications.
Constraints and risks
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