Optical valley Hall effect in gapped graphene for infrared and terahertz light photodetection

Informations projet

VHPC

N° de convention de subvention: 747927

DOI 10.3030/747927

Projet clôturé

Date de signature de la CE 21 Mars 2017

Date de début 22 Août 2017

Date de fin 21 Août 2019

Financé au titre de

• EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions

Coût total € 158 121,60

Contribution de l’UE € 158 121,60

Coordonné par

FUNDACIO INSTITUT DE CIENCIES FOTONIQUES
Spain

Objectif

Modern information processing is based on the degrees of freedom (DOF) of electrons, which are known as charge and spin. Manipulating DOF of electrons is the core function of information-processing unit such as transistor and photodetector. Finding and manipulating new DOF for electrons may open up possibility for next-generation information processing, such as quantum computing. Recently, a new DOF of electrons—valley pseudospin—was found in two dimensional (2D) hexagonal lattices, whose band structures manifest a pair of valleys at the corner of the hexagonal Brillouin zone (labeled as K and -K valley), giving rise to a valley DOF that is in close analogy to electron spin. As 2D hexagonal crystal, graphene, with ultrahigh carrier mobility and ultrafast optoelectronic signal processing ability, has great potential as carrier of valley DOF and intriguing prospect for both fundamental research and practical application of valleytronics. Therefore manipulating valley pseudospin of electrons in graphene would greatly advance the study of valleytronics. This proposal presents the first experimental study of Berry optoelectronics in gapped graphene, in particular extremely strong Valley Hall effects and Valley Hall dynamics. The implementation includes three sections. The first is to break inversion symmetry of graphene crystal by fabricating graphene/boron nitride heterostructure and dual-gate bilayer graphene device. This symmetry breaking allows the Bloch electrons in K and -K valleys to experience valley-contrasted orbital magnetic moments and Berry curvatures, which result in valley-dependent optical selection rule and valley Hall effect. This supplies us paradigm for infrared and terahertz photodetection for section two. In section three, we explore the dynamics of confining charge carriers in a specified valley, by measuring the time-resolved behaviors.

Champ scientifique

• natural sciences › physical sciences › electromagnetism and electronics › optoelectronics
• engineering and technology › nanotechnology › nano-materials › two-dimensional nanostructures › graphene
• engineering and technology › electrical engineering, electronic engineering, information engineering › electronic engineering › sensors › optical sensors
• natural sciences › chemical sciences › inorganic chemistry › metalloids
• natural sciences › computer and information sciences › data science › data processing

Programme(s)

• H2020-EU.1.3. - EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions Main Programme
• H2020-EU.1.3.2. - Nurturing excellence by means of cross-border and cross-sector mobility

Thème(s)

• MSCA-IF-2016 - Individual Fellowships

Appel à propositions

H2020-MSCA-IF-2016

Régime de financement

MSCA-IF-EF-ST - Standard EF

Coordinateur

FUNDACIO INSTITUT DE CIENCIES FOTONIQUES

• Contribution nette de l'UE: € 158 121,60
• Adresse: AVINGUDA CARL FRIEDRICH GAUSS 3 ; 08860 Castelldefels ; Espagne
• Région: Este › Cataluña › Barcelona
• Type d’activité: Research Organisations
• Coût total: € 158 121,60