visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나

Moir\’e fractals in supermoir\’e structures

2024.06.04 11:12

admin 조회 수:2473

날짜 2024-06-05 10:00 
연사  
장소 E6, #2501 
아래와 같이 세미나를 개최하고자 하오니, 관심있는 분들의 많은 참석 부탁드립니다.
 
Date: 10:00 am, 5th Jun (Wed)
 
Place: E6, #2501
 
Speaker: Deepanshu Aggarwal(Physics, Indian Institute of Technology)
 
Title: Moir\’e fractals in supermoir\’e structures
 
Abstract: 

Twisted bilayer graphene (TBLG) subjected to a sequence of commensurate external periodic potentials [for a detailed review, see Ref.3] results in the formation of moir\'{e} fractals (MFs) [ref. 1] that can quantitatively describe the band structure of a large class of super-moir\'{e} systems. The self-similarity of the hierarchy of Brillouin zones (BZ) in such moir\'{e} fractals so produced results in a nested subband structure inside the bandwidth of the original moiré bands, and the number of such sub-bands can be directly computed with the help of fractal dimension. The fractal generators for such MFs are derived, and we examine their effect on the BZ edge hierarchy. We also find parallels between such MFs and those arising in economic geography related to transportation and correspondence within the framework of central place theory. We point out that the concept of MF is quite general and can be easily extended to non-graphene twisted heterostructures. The modification of band structure can strongly influence correlated phase and optical properties[ ref. 2], and various other transport and thermodynamic properties in such twisted heterostructures. Recent work shows lattice relaxations significantly alter the electronic band structure of twisted, layered structures. In further work, we show the robustness of MFs in the presence of lattice distortion-induced strain field and examine whether the number of in-gap states given by the fractal dimension remains the same under such strain [4].


 [1] D Aggarwal, Rohit Narula, and Sankalpa Ghosh, "Moiré fractals in twisted graphene layers," Phys. Rev. B 109, 125302 (2024) (Editor's Suggestion) [2] Disha Arora, Deepanshu Aggarwal, Sankalpa Ghosh, and Rohit Narula, "Interference effects in polarization-controlled Rayleigh scattering in twisted bilayer graphene,"Phys. Rev. B 107, 205423 (2023) [3] Deepanshu Aggarwal, Rohit Narula, and Sankalpa Ghosh "A primer on twistronics: a massless Dirac fermion's journey to moiré patterns and flat bands in twisted bilayer graphene," J. Phys.: Condens. Matter 35 143001 (2023) (Invited Topical Review) [4] Deepanshu Aggarwal, Rohit Narula and Sankalpa Ghosh., Moir\'{e} fractals under strain, (manuscript under preparation)

 
번호 날짜 연사 제목
공지 2025-02-24 16:00    2025년 봄학기 콜로키움 안내
공지 2025-02-27 16:00    2025년 봄 물리학과 특별세미나 (광학/응집물리 분야)
234 2019-06-12 15:00    The relation between free and interacting fermionic SPT phases file
233 2019-06-04 17:00    Stochastic nature of bacterial eradication using antibiotics file
232 2019-05-31 11:00    Cavity QED with Spin Qubits file
231 2019-05-30 16:00    Tuning the excitonic properties of semiconductors with light-matter interactions file
230 2019-05-24 16:00    Infrared spectroscopy study on metal-insulator transitions in layered perovskite iridates file
229 2019-05-21 16:00    Classification of flat bands according to the band-crossing singularity of Bloch wave functions file
228 2019-05-09 16:00    Quantum Optical Sensing Using Single Photons And Single Photon Emission from Single Emitters file
227 2019-05-08 16:00    Imaging valley dependent electron transport in 2D semiconductors file
226 2019-05-03 11:00    Exotic Magnetism file
225 2019-05-02 16:00    Anomalous optical properties of halide perovskites file
224 2019-05-01 16:00    Raman and x-ray scattering study on correlated electron systems: two case examples file
223 2019-04-26 16:00    Robust Quantum Metrology using Strongly Interacting Spin Ensembles and Quantum Convolutional Neural Network file
222 2019-04-23 16:00    From Mott physics to high-temperature superconductivity file
221 2019-04-19 16:00    Graphene and hBN heterostructures file
220 2019-04-19 14:30    A family of finite-temperature electronic phase transitions in graphene multilayers file
219 2019-04-19 11:00    First-principles studies of semiconductors for solar cell applications file
218 2019-04-11 16:00    Massive screening for cathode active materials using deep neural network file
217 2019-04-04 16:00    Chiral spin-photon interaction at nanoscale file
216 2019-03-29 16:00    Coherent Quantum Control and Magnetism on atoms – Trapped ion and ESR STM file
215 2019-03-29 14:30    Epitaxial Multifunctional Oxide Thin Films for Novel Electronics file