visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나

Moir\’e fractals in supermoir\’e structures

2024.06.04 11:12

admin 조회 수:7964

날짜 2024-06-05 10:00 
연사 Deepanshu Aggarwal(Physics, Indian Institute of Technology) 
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 2026-03-09 16:00    2026년 봄학기 콜로키움
공지 2025-09-01 12:00    2025년 가을학기 콜로키움
657 2009-02-23 16:00    Physics Colloquium : 2009 Spring file
656 2009-09-07 16:00    Physics Colloquium : 2009 Fall file
655 2009-10-21 16:00    Interdimensional Universality of Dynamic Interfaces
654 2010-02-08 16:00    Physics Ciolloquium : 2010 Spring file
653 2010-02-14 16:00    Physics Colloquium - 2011 Spring file
652 2010-09-06 16:00    Physics Colloquium : 2010 Fall file
651 2011-05-16 16:00    Photonics with surface plasmon polaritons
650 2011-09-03 16:00    Physics Colloquium : 2011 Fall file
649 2012-02-13 16:00    Physics Colloquium : 2012 Spring
648 2012-04-02 16:00    A new route to ferroelectricity in magnetic spinels: a case of Co2MnO4
647 2013-03-11 16:00    Physics Colloquium : 2013 Spring
646 2013-09-09 16:00    Physics Colloquium : 2013 Fall
645 2014-03-10 16:00    Physics Colloquium : 2014 Spring file
644 2014-05-28 17:00    부품소재산업이 미래다
643 2014-12-22 14:00    Dynamics of molecular motors: Power stroke vs Brownian ratchet file
642 2015-03-04 12:00    Bioimaging and Biosensing Using Near-Infrared Fluorescence file
641 2015-03-09 16:00    Physics Colloquium : 2015 Spring file
640 2015-03-13 14:00    The 15th Innovative Workshop on Soft/Bio Materials file
639 2015-06-03 12:00    The First Wednesday Multidisciplinary Forum file
638 2015-07-15 14:00    Electronic and optical properties of titanate-based oxide superlattices