visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나

Moir\’e fractals in supermoir\’e structures

2024.06.04 11:12

admin 조회 수:8685

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 2026-03-05 16:00    2026년 봄학기 물리학과 특별세미나 (광학/응집물리 분야)
622 2015-11-28 10:00    Electron Tunneling Spectroscopy of Single and Bilayer Graphene with Hexagonal Boron Nitride as Tunneling Barrier
621 2015-12-01 16:00    Introducing extra dimensions to spectroscopic studies of advanced quantum materials
620 2015-12-02 16:00    Samarium Hexaboride: Is it a Topological insulator?
619 2015-12-03 16:00    Hybrid solid state spin qubits in wide bandgap semiconductors
618 2015-12-09 11:00    Functional Imaging & Monitoring of Brain & Breast with Diffuse Light
617 2015-12-09 14:00    SWELLABLE COLLOIDAL PARTICLES ARE SWELL
616 2015-12-11 13:30    Quantum spin liquid in the 1/3 depleted triangular lattice Ba3(Ru1-xIrx)Ti2O9
615 2015-12-11 15:45    Dynamical mean field theory studies on heavy fermion system
614 2015-12-17 11:00    Wavefront engineering for in-vivo Deep brain imaging
613 2016-01-11 16:00    Mott Physics in the Strong Spin-Orbit Coupling Regime
612 2016-01-26 14:00    Electrochemistry on Nano- and Atomic Levels: Scanning Probe Microscopy Meets Deep Data
611 2016-03-07 16:00    Physics Colloquium : 2016 Spring file
610 2016-03-11 13:30    Topological phases of matter in nonequilibrium: Topology of the Wannier-Stark ladder
609 2016-03-11 13:30    Physics Seminar Serises : 2016 Spring file
608 2016-03-11 16:00    Jan. Switching handedness of of chiral solitons in Z4 topological insulators
607 2016-04-01 14:30    Interference of single charged particles without a loop and dynamic nonlocality
606 2016-04-01 16:15    Cotunneling drag effect in Coulomb-coupled quantum dots
605 2016-04-04 09:30    Radio frequency engineering
604 2016-04-05 16:00    A new impurity solver for multi-orbital systems: adaptive truncation of the Hilbert space
603 2016-04-06 15:30    Superconducting Quantum Interference Devices for Precision Detection