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Strong magnetoresistance in a graphene Corbino disk at low magnetic fields

Kamada, Masahiro; Gall, Vanessa 1,2; Sarkar, Jayanta; Kumar, Manohar; Laitinen, Antti; Gornyi, Igor 1,2; Hakonen, Pertti
1 Institut für Theorie der Kondensierten Materie (TKM), Karlsruher Institut für Technologie (KIT)
2 Institut für QuantenMaterialien und Technologien (IQMT), Karlsruher Institut für Technologie (KIT)

Abstract (englisch):

We have measured magnetoresistance of suspended graphene in the Corbino geometry at magnetic fields up
to B = 0.15 T, i.e., in a regime uninfluenced by Shubnikov—de Haas oscillations. The low-temperature relative
magnetoresistance [R(B) − R(0)]/R(0) is strong, approaching 100% at the highest magnetic field studied, with
a quite weak temperature dependence below 30 K. A decrease in the relative magnetoresistance by a factor of
two is found when charge carrier density is increased to |n| 3 × 1010 cm−2. Furthermore, we find a shift in the
position of the charge neutrality point with increasing magnetic field, which suggests that magnetic field changes
the screening of Coulomb impurities around the Dirac point. The gate dependence of the magnetoresistance
allows us to characterize the role of scattering on long-range (Coulomb impurities, ripples) and short-range
disorder (adatoms, atomic defects), as well as to separate the bulk resistance from the contact one. Based on the
analysis of the magnetoresistance, we propose a more reliable method to extract the bulk mobility, which does
not require prior knowledge of the contact resistance. ... mehr


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Originalveröffentlichung
DOI: 10.1103/PhysRevB.104.115432
Scopus
Zitationen: 15
Web of Science
Zitationen: 14
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Zitationen: 19
Zugehörige Institution(en) am KIT Institut für QuantenMaterialien und Technologien (IQMT)
Institut für Theorie der Kondensierten Materie (TKM)
Publikationstyp Zeitschriftenaufsatz
Publikationsmonat/-jahr 09.2021
Sprache Englisch
Identifikator ISSN: 2469-9950, 2469-9969
KITopen-ID: 1000138881
HGF-Programm 47.12.01 (POF IV, LK 01) Advanced Solid-State Qubits and Qubit Systems
Erschienen in Physical Review B
Verlag American Physical Society (APS)
Band 104
Heft 11
Seiten Article no: 115432
Vorab online veröffentlicht am 29.09.2021
Nachgewiesen in Scopus
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Web of Science
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