visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나
날짜 2022-06-03 11:00 
일시 June 3(Fri.) 11:00 
장소 E6-2 #1323 
연사 Prof. Gil Young Cho (Department of Physics, POSTECH) 
1. Date / Time 
    - June  3, 2022
    - 11:00 AM (KST)
 
2. Place / ZOOM 
    - Room 1323, KAIST Natural Sciences Lecture Hall(E6-2) (자연과학동 1323호)
 
3. Speaker
    - Prof. Gil Young Cho (Department of Physics, POSTECH)
 
4. Talk Title
    - Theoretical Investigation of Exotic Quantum States in Low-dimensional Materials
 
5. Abstract
    -  Because of the enhanced quantum fluctuations, low-dimensional quantum materials provide a natural platform for exotic emerging phenomena. The archetypical examples include Tomonaga-Luttinger liquids, fractional quantum Hall states, and high-Tc superconductivity. More recently, several new members of exotic quantum states have been discovered in novel low-dimensional materials such as twisted van der Waals materials and 2D charge-density wave materials. 
 
       In the first part of this talk, we will primarily focus on the so-called conducting network systems, where 1D metallic wires form a periodic 2D superstructure. Such structure naturally appears in several of twisted 2D materials, and also in some charge-density wave materials [2], where domain walls form a regular 2D network superstructure. For these network systems, we first theoretically prove [1] that they realize robust flatbands, which can naturally explain the enhanced superconductivity. We also show that corner states, which are a hallmark of the higher-order topological insulators [4], appear in the network superstructure. Next, we theoretically show that a remarkably wide variety of new non-Fermi liquids emerge and that these non-Fermi liquids can be classified by the characteristics of the junctions in networks [3]. Using this, we calculate the electric conductivity of the non-Fermi liquids as a function of temperature, which show markedly different scaling behaviors than a regular 2D Fermi liquid. 
 
        If time allows, we will also discuss the future research and present their perspectives, which include the experimental recipes for the realization and theoretical characterization of steady Floquet states [5] and the classification of quantum phases of matter.   
 

References 

[1] J. Lee, C. Geng, J. Park, M. Oshikawa, S. Lee, H. Yeom, and GYC*, Physical Review Letters (2019)

[2] J. Park, GYC, J. Lee, and H. Yeom*, Nature Communications (2019) 

[3] J. Lee, M. Oshikawa, and GYC*, Physical Review Letters (2021)

[4] B. Kang, W. Lee, and GYC*, Physical Review Letters (2021) 

[5] S. Park, W. Lee, S. Jang, Y. Choi, J. Park, W. Jung, K. Watanabe, T. Taniguchi, GYC*, G. Lee*, Nature (2022)

번호 날짜 장소 제목
311 2019-04-19 16:00  E6-2. 1st fl. #1323  Graphene and hBN heterostructures file
310 2019-04-23 16:00  #1323, E6-2  From Mott physics to high-temperature superconductivity file
309 2019-04-26 16:00  #1323, E6-2  Robust Quantum Metrology using Strongly Interacting Spin Ensembles and Quantum Convolutional Neural Network file
308 2019-05-01 16:00  #1323, E6-2  Raman and x-ray scattering study on correlated electron systems: two case examples file
307 2019-05-02 16:00  #1323, E6-2  Anomalous optical properties of halide perovskites file
306 2019-05-03 11:00  E6-2. 2st fl. #2502  Exotic Magnetism file
305 2019-05-08 16:00  E6 Room(#1323)  Imaging valley dependent electron transport in 2D semiconductors file
304 2019-05-09 16:00  #1323, E6-2  Quantum Optical Sensing Using Single Photons And Single Photon Emission from Single Emitters file
303 2019-05-21 16:00  #5318, E6-2  Classification of flat bands according to the band-crossing singularity of Bloch wave functions file
302 2019-05-24 16:00  #1323, E6-2  Infrared spectroscopy study on metal-insulator transitions in layered perovskite iridates file
301 2019-05-30 16:00  #1323, E6-2  Tuning the excitonic properties of semiconductors with light-matter interactions file
300 2019-05-31 11:00  #1323, E6-2  Cavity QED with Spin Qubits file
299 2019-06-04 17:00  #1323, E6-2  Stochastic nature of bacterial eradication using antibiotics file
298 2019-06-12 15:00  Rm# 1323, E6-2  The relation between free and interacting fermionic SPT phases file
297 2019-06-17 10:30  #1323, E6-2  Chiral Spintronics file
296 2019-06-24 11:00  E6-2, #1323  Topological photonic anomalies file
295 2019-06-27 14:00  #2502, E6-2  Gapless Kitaev Spin Liquid to Loop and String Gases file
294 2019-06-28 13:30  #1323, E6-2  Magnetic domains and domain wall conduction in pyrochlore iridate thin films and heterostructures file
293 2019-06-28 14:00  E6-2, #1322  1st Research-exchange meeting of computational material physics file
292 2019-07-03 15:00  E6-2, 2501  Many-body quantum electrodynamis (QED) with atoms and photons: A new platform for quantum optics" file