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相关论文: Second harmonic generation control in twisted bila…

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Twisted bilayer (t-BL) transition metal dichalcogenides (TMDCs) attracted considerable attention in recent years due to their distinctive electronic properties, which arise due to the moire superlattices that lead to the emergence of flat…

The possibility of the formation of an electron-hole liquid in the type II heterostructures based on monolayers (bilayers) of transition metal dichalcogenides is considered. It is indicated that additional valleys in the conduction band,…

介观与纳米尺度物理 · 物理学 2022-06-22 Pavel V. Ratnikov

The quantum spin Hall effect has been predicted in twisted homobilayer transition metal dichalcogenides (TMDs) owing to the layer-pseudospin magnetic field. Recently, experimental observations have also confirmed such topological states of…

介观与纳米尺度物理 · 物理学 2025-08-08 Hao He , Zhao Gong , Qing-Jun Tong , Dawei Zhai , Wang Yao , Xing-Tao An

The large surface-to-volume ratio in atomically thin 2D materials allows to efficiently tune their properties through modifications of their environment. Artificial stacking of two monolayers into a bilayer leads to an overlap of…

介观与纳米尺度物理 · 物理学 2020-05-14 Samuel Brem , Kai-Qiang Lin , Roland Gillen , Jonas M. Bauer , Janina Maultzsch , John M. Lupton , Ermin Malic

Monolayers of transition metal dichacogenides show strong second-order nonlinearity and symmetry-driven selection rules from their three-fold lattice symmetry. This process resembles the valley-contrasting selection rules for…

Moir\'{e} interference effects have profound impact on the optoelectronic properties of vertical van der Waals structures. Here we establish secondary electron imaging in a scanning electron microscope as a powerful technique for…

介观与纳米尺度物理 · 物理学 2023-06-27 Anna Rupp , Jonas Göser , Zhijie Li , Ismail Bilgin , Anvar Baimuratov , Alexander Högele

Twisted van der Waals heterostructures unravel a new platform to study strongly correlated quantum phases. The interlayer coupling in these heterostructures is sensitive to twist angles ($\theta$) and key to controllably tune several exotic…

材料科学 · 物理学 2019-12-03 Rahul Debnath , Indrajit Maity , Manish Jain , Arindam Ghosh

Integrating 2D materials onto on-chip photonic devices holds significant potential for nonlinear frequency conversion across various applications. The lack of inversion symmetry in monolayers of transition metal dichalcogenides (TMDs),…

Structural engineering of van der Waals heterostructures via stacking and twisting has recently been used to create moir\'e superlattices, enabling the realization of new optical and electronic properties in solid-state systems. In…

A major theoretical challenge of studying twisted transition metal dichalcogenide (TMD) bilayers is that the unit cell of such structures is very large and therefore difficult to address using first-principles methods. However, twisted TMD…

材料科学 · 物理学 2019-09-13 Madeleine Phillips , C. Stephen Hellberg

Excitons in bilayer transition metal dichalcogenides (2L-TMDs) are Coulomb-bound electron/hole pairs that can be viewed as broadly tunable analogs of atomic or molecular systems. Here, we study the properties of 2L-TMD excitons under strong…

介观与纳米尺度物理 · 物理学 2023-03-20 S. Kovalchuk , K. Greben , A. Kumar , S. Pessel , K. Watanabe , T. Taniguchi , D. Christiansen , M. Selig , A. Knorr , K. I. Bolotin

Van der Waals heterostructures composed of transition metal dichalcogenide monolayers (TMDs) are characterized by their truly rich excitonic properties which are determined by their structural, geometric and electronic properties: In…

Twist engineering, or the alignment of two-dimensional (2D) crystalline layers with desired orientations, has led to tremendous success in modulating the charge degree of freedom in hetero- and homo-structures, in particular, in achieving…

In order to shed light on the second harmonic generation (SHG) of new 2-D systems, first principles methods are used to calculate the second order susceptibility \chi(2) for different types of layered alloys such as monolayers of transition…

材料科学 · 物理学 2017-11-21 Michael C. Lucking , Kory Beach , Humberto Terrones

We identify an optical excitation mechanism that transfers a valley polarization from photo-excited electron-hole pairs to free charge carriers in twisted WSe$_2$/MoSe$_2$ heterobilayers. For small twist angles, the valley lifetimes of the…

Coherent coupling between excitons is at the heart of many-body interactions with transition metal dichalcogenide (TMD) heterostructures as an emergent platform for the investigation of these interactions. We employ multi-dimensional…

介观与纳米尺度物理 · 物理学 2022-01-05 Torben L. Purz , Eric W. Martin , Pasqual Rivera , William G. Holtzmann , Xiaodong Xu , Steven T. Cundiff

We study the effects of heterostrain on moir\'e bands in twisted bilayer graphene and bilayer transition metal dichalcogenide (TMD) systems. For bilayer graphene with twist angle near $1^\circ$, we show that heterostrain significantly…

材料科学 · 物理学 2019-08-07 Zhen Bi , Noah F. Q. Yuan , Liang Fu

We investigate excitons in stacked transition metal dichalcogenide (TMDC) layers under perpendicularly applied electric field, herein MoSe$_2$/WSe$_2$ van der Waals heterostructures. Band structures are obtained with density functional…

介观与纳米尺度物理 · 物理学 2018-09-19 A. Chaves , J. G. Azadani , V. Ongun Özçelik , R. Grassi , T. Low

Transition Metal Dichalcogenides (TMDs) are one of the most studied two-dimensional materials in the last 5-10 years due to their extremely interesting layer dependent properties. Despite the presence of vast research work on TMDs, the…

化学物理 · 物理学 2019-11-27 Kamalika Ghatak , Kyung Nam Kang , Eui-Hyeok Yang , Dibakar Datta

The quantum spin Hall (QSH) effect, characterized by topologically protected spin-polarized edge states, was recently demonstrated in monolayers of the transition metal dichalcogenide (TMD) WTe$_2$. However, the robustness of this…

介观与纳米尺度物理 · 物理学 2024-05-07 Felix Lüpke , Dacen Waters , Anh D. Pham , Jiaqiang Yan , David G. Mandrus , Panchapakesan Ganesh , Benjamin M. Hunt