IN-PERSON EVENT - REGISTER HERE \;to attend
\nBy Prof. Alexey Berdyugin \;- National University of Singapore
\nAbstract: Electrostatic screening is a powerful way to tune electron-electro n interactions\, central to phenomena like correlated insulators\, charge density waves\, and superconductivity. In the first part of my talk\, I wi ll present a double-layer graphene system with a large twist angle\, allow ing independent control over the carrier density in each layer. By doping one layer\, we suppress charge inhomogeneities in the other\, enabling Lan dau quantization at just a few mT which corresponds to the quantum mobilit y exceeding that of state-of-the-art GaAs 2DEGs. We also observe a robust bandgap in ultra-clean graphene and discuss its possible origins. In the s econd part\, I will show how screening affects correlations in magic-angle TBG. In tetralayer devices with two decoupled TBG layers\, doping the sec ondary TBG suppresses both correlated insulator gaps and superconductivity in the primary one. This highlights the role of screening in tuning corre lations and offers insight into the mechanisms behind superconductivity in TBG.
\nShort Bio: \;Prof. Alexey Berdyugin received his bachelor’s and master’s degree s in condensed matter physics from Moscow Phystech in 2016. Next\, he cond ucted doctoral research at the University of Manchester under the supervis ion of Nobel Prize laureate\, Sir. Andre Geim. In 2022\, Dr Berdyugin join ed the National University of Singapore as an Assistant Professor\, where he has received the NUS Presidential Young Professorship award\, and more recently National Research Foundation (NRF) of Singapore Fellowship Award 2024. Research works of Dr Berdyugin have pioneered the non-linear electro n transport studies of the novel twisted heterostructures which resulted i n the discovery of a novel current propagation regime\, as well as electro n hydrodynamic and the giant magnetoresistance effect recently discovered in high-quality graphene heterostructures.
\nHosted by \;Doctor Roshan Krishna Kumar\,
\; Ultrafast Dynamics in Nanoscale Systems \;Team \;Leader.<
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