Quantum-dot assisted spectroscopy of degeneracy-lifted Landau levels in graphene.
Journal
Nature communications
ISSN: 2041-1723
Titre abrégé: Nat Commun
Pays: England
ID NLM: 101528555
Informations de publication
Date de publication:
08 Jul 2020
08 Jul 2020
Historique:
received:
30
03
2020
accepted:
17
06
2020
entrez:
10
7
2020
pubmed:
10
7
2020
medline:
10
7
2020
Statut:
epublish
Résumé
Energy spectroscopy of strongly interacting phases requires probes which minimize screening while retaining spectral resolution and local sensitivity. Here, we demonstrate that such probes can be realized using atomic sized quantum dots bound to defects in hexagonal Boron Nitride tunnel barriers, placed at nanometric distance from graphene. With dot energies capacitively tuned by a planar graphite electrode, dot-assisted tunneling becomes highly sensitive to the graphene excitation spectrum. The spectra track the onset of degeneracy lifting with magnetic field at the ground state, and at unoccupied excited states, revealing symmetry-broken gaps which develop steeply with magnetic field - corresponding to Landé g factors as high as 160. Measured up to B = 33 T, spectra exhibit a primary energy split between spin-polarized excited states, and a secondary spin-dependent valley-split. Our results show that defect dots probe the spectra while minimizing local screening, and are thus exceptionally sensitive to interacting states.
Identifiants
pubmed: 32641683
doi: 10.1038/s41467-020-17225-1
pii: 10.1038/s41467-020-17225-1
pmc: PMC7343833
doi:
Types de publication
Journal Article
Langues
eng
Sous-ensembles de citation
IM
Pagination
3408Subventions
Organisme : EC | Horizon 2020 Framework Programme (EU Framework Programme for Research and Innovation H2020)
ID : 637298
Organisme : Israel Science Foundation (ISF)
ID : 994/19
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