korean english


Home > 게시판 > 세미나

아래와 같이 콜로퀴움을 개최하오니 많이 참석해 주시기 바랍니다. 4시 20분부터 2층 라운지세미나실에 다과를 준비하오니 많은 참석 부탁드립니다 아 래 제목: Fractional Hall Physics of Epitaxial Graphene: Scanning Tunneling Spectroscopy Study at 20 mK with High Magnetic Field 연사: 송 영 재 박사(National Institute of Standards and Technology ) 일시: 2010년 3월 26일(금) 오후4:30 장소: 물리학과 세미나실(31355호실) 초록: Graphene, two dimensional carbon system sharing the same mother form with C60 and carbon nanotubes, is an ideal two dimensional electron system (2DES) with one atomic thickness and has unique electronic properties unlike any other materials yet studied [1]. Completely new physics emerges when quantum interactions dominate as graphene’s relativistic electrons are put under the extreme conditions of low temperatures and high magnetic fields [2,3]. Here I introduce the first scanning tunnelling spectroscopy measurements for the electron density of states of graphene in fields up to 14 T and at temperatures below 20 mK [4] by an ultra low temperature scanning tunneling microscope [5] that I constructed recently in NIST. The Landau levels, peaks in the density of states in a magnetic field, split into a quartet of states as both spin and valley (pseudo-spin) degeneracies are lifted. The valley splitting is much larger than the spin splitting and both show evidence of strong quantum exchange interaction effects. At particular fields when N=1 landau level peak locates on the Fermi level, the spectroscopy shows evidence of a new series of fractional quantum Hall states such as filling factors of 11/2, 9/2 and 7/2 as well as enhanced spin/valley splitting by exchange coupling. The spatial mapping for graphene’s even-filling, polarized odd-filling and fractional-filling states will be addressed, which has been a key issue as a phase-driven problem in 2DES for last decades.
번호 제목 날짜 조회 수
공지 <12/8(Thu.) 11:00am>노벨상 소개 강연 - 2016년 노벨 물리학상: 위상 응집 물리의 탄생 2016.11.28 1058812
326 <5/21> Magnetism and Superconductivity 2014.05.14 110911
325 2018학년도 1학기 콜로퀴움 일정 2018.01.03 110020
324 <10/15> Electric control of magnetic nanostructures via spin torque 2010.10.08 109980
323 <5/1> Entanglement and topological order in 1D and 2D systems 2013.04.18 109429
322 <5/28> The hunt for high energy neutrinos with IceCube - more evidence for their astrophysical origin 2014.05.22 108936
321 <May 17(Wed.) 4:30 PM>Printed Electronics 2017.05.10 108480
320 <4/13> Introduction to Quantum Information Processing 2007.04.11 108220
319 <12/4> The "Physics" of Climate Change 2009.12.02 107588
318 2017학년도 2학기 콜로퀴움 일정 2017.07.04 107075
317 <11/13> Computer-Aided Engineering for Nucleic Acid Nanostructures 2013.11.07 106704
316 <11/16> Study of carrier transport and charging effects in organic devices 2011.11.10 106665
315 <6/8> 액체금속 및 물의 과냉각 현상과 국소구조와의 관계 : 정전기 공중부양 기술 및 dynamic diamond anvil cell 2011.06.07 106469
314 <9/11> Complex networks in technology, biology and sociology 2009.09.04 106429
313 <4/27> RENO Reactor Neutrino Experiment 2011.04.18 106408
312 <5/27(수) 오후4:30분>Controlling phases in epitaxial transition metal oxide thin films 2015.05.21 106151
311 2014학년도 2학기 콜로퀴움 일정 2014.09.11 105973
310 <Nov. 8(Wed.) 4:30 PM> 연성물질 기반 위상학적 결함구조의 상전이와 응 2017.11.01 105968
309 <11/9> Bosons in high Tc superconductors: an experimental survey 2011.10.31 105712
308 <4/16> Lasers, Microscopes, and Superconductors: Laser Scanning Microscopy of Superconducting Circuits 2014.04.10 104923
307 <6/2>백색 LED를 이용한 반도체조명에 관하여 2006.05.29 104635