| 主讲人简介： |
Prof. Yannick J. Dappe obtained his PhD at Strasbourg University in 2002 on the theory of nonlinear optics on metallic surfaces. He went to the group of Prof. F. Flores at the Autonomous University in Madrid (2004-2008) to learn Density functional Theory (DFT) methods and developed expertise in theory of van der Waals interactions in graphene and carbon materials, and electronic properties of molecules on surfaces. Since 2008, he is CNRS researcher, now at the Condensed Matter Physics Laboratory (SPEC) of the CEA Saclay. His main research interests focus on the theoretical study of graphene, 2D materials and van der Waals heterostructures, charge density waves in 2D materials, electronic transport in nanostructures, STM image simulations and Molecular Electronics, using DFT and Keldysh-Green methods. He has authored and co-authored more than 130 articles in scientific journals.
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| 报告内容简介： |
Layered transition metal dichalcogenides (TMDs) host a plethora of exotic ground states such as superconductivity, Mott insulator, and charge density wave (CDW) states. Unlike the one-dimensional case of CDWs, a typical manifestation of Peierls distortion, understanding the origin of CDWs in two and three-dimensional materials is compounded by other mechanisms such as q-dependent electron-phonon coupling or excitonic CDW. Besides the highly fundamental interest in understanding these fascinating electronic structures, the control of CDW phases can be exploited for various applications such as oscillators and data storage. In that respect, intercalated compounds represent an interesting solution to modify CDW phases. Also, in cases of coexisting multiple CDW states in a material, the question of whether switching between these CDWs can be manipulated or controlled has been studied less. In this seminar, Prof. Dappe will present recent experimental and theoretical results on the formation, trough alkali intercalation, and manipulation using a Scanning Tunneling Microscope (STM) tip, of CDW phases in 2D materials. He will show how it is possible to induce transitions and to manipulate CDW phases, leading to potential applications.
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