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Roy R, Holec D, Michal L, Hemzal D, Sarkar S, Sandeep Kumar G, Nečas D, Dhankhar M, Kaushik P, Jénnifer Gómez I, Zajíčková L. Possible charge ordering and anomalous transport in graphene/graphene quantum dot heterostructure. J Phys Condens Matter 2024; 36:265601. [PMID: 38457842 DOI: 10.1088/1361-648x/ad31bf] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 03/08/2024] [Indexed: 03/10/2024]
Abstract
Observations of superconductivity and charge density waves (CDW) in graphene have been elusive thus far due to weak electron-phonon coupling (EPC) interactions. Here, we report a unique observation of anomalous transport and multiple charge ordering phases at high temperatures (T1∼213K,T2∼325K) in a 0D-2D van der Waals (vdW) heterostructure comprising of single layer graphene (SLG) and functionalized (amine) graphene quantum dots (GQD). The presence of functionalized GQD contributed to charge transfer with shifting of the Dirac point ∼ 0.05 eV above the Fermi level (ab initio simulations) and carrier densityn∼-0.3×1012 cm-2confirming p-doping in SLG and two-fold increase in EPC interaction was achieved. Moreover, we elucidate the interplay between electron-electron and electron-phonon interactions to substantiate high temperature EPC driven charge ordering in the heterostructure through analyses of magnetotransport and weak anti-localization (WAL) framework. Our results provide impetus to investigate strongly correlated phenomena such as CDW and superconducting phase transitions in novel graphene based heterostructures.
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Affiliation(s)
- Rajarshi Roy
- Central European Institute of Technology, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic
| | - David Holec
- Department of Materials Science, Montanuniversität Leoben, Franz-Josef-Strasse 18, A-8700 Leoben, Austria
| | - Lukáš Michal
- Central European Institute of Technology, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic
| | - Dušan Hemzal
- Department of Condensed Matter Physics, Masaryk University, Kotlářská, 611 37 Brno, Czech Republic
| | - Saikat Sarkar
- Thin Film and Nanoscience Lab, Department of Physics, Jadavpur University, Kolkata 700032, India
| | - Gundam Sandeep Kumar
- Department of Chemistry, KU Leuven, Celestijnenlaan 200 F, 3001 Heverlee, Belgium
| | - David Nečas
- Central European Institute of Technology, Brno University of Technology, Purkyňova 123, 612 00 Brno, Czech Republic
| | - Meena Dhankhar
- National Centre for Nano Fabrication and Characterization, Oersteds Plads-Building 347, Kongens Lyngby 2800 DK, Denmark
| | - Preeti Kaushik
- Department of Condensed Matter Physics, Masaryk University, Kotlářská, 611 37 Brno, Czech Republic
| | - I Jénnifer Gómez
- Department of Condensed Matter Physics, Masaryk University, Kotlářská, 611 37 Brno, Czech Republic
- Centro Interdisciplinar de Química e Bioloxía (CICA), Universidade da Coruña, Rúa as Carballeiras, 15071 A Coruña, Spain
| | - Lenka Zajíčková
- Department of Condensed Matter Physics, Masaryk University, Kotlářská, 611 37 Brno, Czech Republic
- Central European Institute of Technology, Brno University of Technology, Purkyňova 123, 612 00 Brno, Czech Republic
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Dhankhar M, Vaňatka M, Urbanek M. Fabrication of Magnetic Nanostructures on Silicon Nitride Membranes for Magnetic Vortex Studies Using Transmission Microscopy Techniques. J Vis Exp 2018. [PMID: 30010671 PMCID: PMC6102033 DOI: 10.3791/57817] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Electron and x-ray magnetic microscopies allow for high-resolution magnetic imaging down to tens of nanometers. However, the samples need to be prepared on transparent membranes which are very fragile and difficult to manipulate. We present processes for the fabrication of samples with magnetic micro- and nanostructures with spin configurations forming magnetic vortices suitable for Lorentz transmission electron microscopy and magnetic transmission x-ray microscopy studies. The samples are prepared on silicon nitride membranes and the fabrication consists of a spin coating, UV and electron-beam lithography, the chemical development of the resist, and the evaporation of the magnetic material followed by a lift-off process forming the final magnetic structures. The samples for the Lorentz transmission electron microscopy consist of magnetic nanodiscs prepared in a single lithography step. The samples for the magnetic x-ray transmission microscopy are used for time-resolved magnetization dynamic experiments, and magnetic nanodiscs are placed on a waveguide which is used for the generation of repeatable magnetic field pulses by passing an electric current through the waveguide. The waveguide is created in an extra lithography step.
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Mukharjee S, Mitra D, Sen A, Chattopadhyay A, Kajal S, Dhankhar M. Intubation of a neonate with glossopalatine ankylosis using a paraglossal approach and a laryngoscope with a straight blade. Southern African Journal of Anaesthesia and Analgesia 2014. [DOI: 10.1080/22201181.2014.979629] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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