visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나

Moir\’e fractals in supermoir\’e structures

2024.06.04 11:12

admin 조회 수:166

날짜 2024-06-05 10:00 
일시 Jun 5th (Wed), 10:00am 
장소 E6, #2501 
연사 Deepanshu Aggarwal(Physics, Indian Institute of Technology) 
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 장소 제목
188 2022-04-25 16:00  E6, #1501  Ultrafast electron beam, a tool to explore the nanoscopic world of materials(우리말강의)
187 2022-04-28 16:00  E6 1323  (광학분야 특별세미나)Adiabaticity and symmetry in optical waveguide design
186 2022-05-02 16:00  E6, #1501  What can we learn from the history of science and technology?(우리말강의)
185 2022-05-09 16:00  E6, #1501  Searching for new electronic properties in correlated material flatland
184 2022-05-10 16:00  E6 1323  (광학분야 특별세미나)Testing quantum thermodynamics using quantum optics
183 2022-05-11 16:00  E6-2. #1323 & Zoom  Gravity as a phenomenon in quantum dynamics
182 2022-05-12 16:00  E6-2. #1323 & Zoom  New frontiers of electroweak physics at the LHC
181 2022-05-13 14:30  Zoom webinar  Topological Superconducting Spintronics Towards Zero-Power Computing Technologies file
180 2022-05-13 16:00  자연과학동(E6-2) 1st fl. #1323  High-fidelity iToffoli gate for fixed-frequency superconducting qubits file
179 2022-05-16 16:00  E6, #1501  Design synthetic topological matter with atoms and lights
178 2022-05-18 16:00  E6-2. #1323 & Zoom  Geometry, Algebra, and Quantum Field Theory
177 2022-05-19 15:00  online  (광학분야 특별세미나)Development of a multimodal optical system for improved disease diagnosis
176 2022-05-19 15:00  online  (광학분야 특별세미나)Development of a multimodal optical system for improved disease diagnosis
175 2022-05-19 16:00  E6-2. #1323 & Zoom  Chasing Long Standing Neutrino Anomalies with MicroBooNE
174 2022-05-20 11:00  E6-1 #1323  (응집물리 세미나) Exploration of new polymorphs in van der Waals crystals
173 2022-05-23 16:00  E6, #1501  Novel electronic transport in topological van der Waals magnets
172 2022-05-25 14:00  E6 Room(#2501)  Atomic-level insights into ferroelectric switching and preferred orientation of ultrathin hafnia file
171 2022-05-25 16:00  E6-2. 1st fl. #1323 / Zoom  Uncovering New Lampposts for Dark Matter: Continuum or Conformal
170 2022-05-26 16:00  E6 1323  (광학분야 특별세미나)Topological photonic devices
169 2022-05-27 11:00  Online seminar  Current Status and Future Plans of ADMX file