visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나
날짜 2016-11-18 10:30 
일시 Nov. 18th (Fri) 10:30 a.m. 
장소 #5318(5th fl.) 
연사 Dr. 최 순 원, Havard University 

Non-equilibrium many-body spin dynamics in diamond

 

Dr. 원, Havard University

Nov. 18th (Fri) 10:30 a.m., #5318(5th fl.)

 

 

Abstract:

In this talk, we will discuss two recent developments in non-equilibrium quantum dynamics of strongly interacting many-body systems: I. critically slow thermalization in a disordered dipolar spin ensemble [1] and II. the observation of discrete time crystalline order [2]. Both of these experiments were enabled by a high density ensemble of nitrogen-vacancy (NV) color centers in diamond [3]. As a mixture of theory and experiments, the talk will be self-contained and pedagogical, reviewing some of basic concepts in many-body localization, Floquet time-crystal, spin properties of NV centers and experimental techniques to manipulate and engineer the dynamics.

Part I:

Statistical mechanics underlies our understanding of macroscopic quantum systems. It is based on the assumption that out-of-equilibrium systems rapidly approach their equilibrium states, forgetting any information about their microscopic initial conditions. This fundamental paradigm is challenged by disordered systems, in which a slowdown or even absence of thermalization is expected. By controlling the spin states of the ~10^6 NV centers, we observe slow, sub-exponential thermalization consistent with power laws that exhibit disorder-dependent exponents; this behavior is modified at late times owing to many-body interactions. These observations are quantitatively explained by a resonance counting theory that incorporates the effects of both disorder and interactions

Part II:

The interplay of periodic driving, disorder, and strong interactions has recently been predicted to result in exotic ``time-crystalline'' phases, which spontaneously break the discrete time-translation symmetry of the underlying drive. We report the experimental observation of such discrete time-crystalline order and the observation of long-lived temporal correlations at integer multiples of the fundamental driving period. We experimentally identify the phase boundary and find that the temporal order is protected by strong interactions; this order is remarkably stable against perturbations, even in the presence of slow thermalization. We provide a theoretical description of approximate Floquet eigenstates of the system based on product state ansatz and predict the phase boundary, which is in qualitative agreement with our observations.

 

[1] G. Kucsko et al, arXiv:1609.08216

[2] S. Choi et al, arXiv:1610.08057

[3] J. Choi et al, arXiv:1608.05471

 

Contact: Eun-Gook Moon, Physics Dept., (egmoon@kaist.ac.kr)

 

번호 날짜 장소 제목
공지 2022-10-24 16:00  E6 #1501(공동강의실)  Physics Colloquim(Fall 2022)
공지 2022-09-21 10:30  E6-1 #1501  [Update 세미나 영상] Distinguished Lecture 'The Magic of Moiré Quantum Matter' Prof. Pablo Jarillo-Herrero(Department of Physics, MIT)
공지 2022-11-11 11:00  E6-2 #1323  [Update 세미나영상] (응집물리 세미나) Honeycomb oxide heterostructures for quantum spin liquid
공지 2022-10-28 11:00  E6-2 #1323  [Update 세미나영상] (응집물리 세미나) Machine-Learning-Guided Prediction models and Materials discovery for high Tc cuprates
공지 2022-10-07 11:00  E6-2 #1323  [Update 세미나 영상] (응집물리 세미나) Competing orders in a vanadium-based kagome metal monolayer
공지 2022-09-23 11:00  E6-2 #1323  [Update 세미나 영상] (응집물리 세미나) Steady Floquet-Andreev states in graphene Josephson junctions
공지 2022-09-22 11:00  E6-1 #1323  2022 가을학기 응집물리 및 광학 세미나 전체 일정
129 2017-05-12 13:30  E6-2. 1st fl. #1323  Topological Dirac insulator
128 2017-04-28 16:00  #1323 (E6-2. 1st fl.)  Carbon nanotubes coupled to superconducting impedance matching circuits
127 2017-04-28 14:30  E6-2. 1st fl. #1323  Hot electron generation at surfaces and its impact to catalysis and renewable energy conversion
126 2017-04-27 16:00  Seminar Room(#1323, E6-2)  반도체 양자점을 이용한 단광자 광원
125 2017-04-06 16:00  IBS CAPP seminar room, Creation Hall (3F), KAIST Munji Campus  For whom the Belle tolls
124 2017-04-05 12:00  Room 101, Creative Learning Bldg.(E11)  2017년 4월 첫수 융합포럼 개최 안내(물리학과 & 원자력 및 양자공학과 공동 개최)/The First Wednesday Multidisciplinary Forum in April 2017 organized by Dept. of Physics & Dept. of Nuclear & Quantum Engineering file
123 2017-03-24 16:00  #1323 (1st fl. E6-2)  Graphene based nano electronics and nano electromechanics; focusing on precise control of nano structures for studying accurate physical properties
122 2017-03-24 14:30  #1323 (1st fl. E6-2).  Topological Dynamics
121 2017-03-21 16:00  Seminar Room 1323  Spring 2017: Physics Seminar Serises file
120 2017-03-06 16:00  Seminar Room 1501  Spring 2017: Physics Colloquium file
119 2017-03-02 16:00  #1323(E6-2. 1st fl.)  “Progress in the comparison of ARPES to DMFT for d and f strongly correlated electron systems”
118 2017-02-01 14:00  #1323(E6-2. 1st fl.)  Quantum electron optics using flying electrons
117 2017-01-09 16:00  Lecture Hall, College of Natural Sciences [#1501,E6-2]  Topological Defects and Phase Transitions" file
116 2016-12-8 16:00  #1323(E6-2. 1st fl.)  Dynamical Resonance between Two Optical Cavities via Optomechanical Oscillator
115 2016-12-12 13:30  1:30p.m. #1323(E6-2. 1st fl.)  “Possible symmetry in the phase diagrams of electron- & hole-doped cuprate high-Tc superconductors”
114 2016-12-09 16:00  #1323(E6-2. 1st fl.  Shift Charge and Spin Photocurrents in Dirac Surface States of Topological Insulator
113 2016-12-09 13:30  #1323(E6-2. 1st fl.)  Entanglement area law in strongly-correlated systems
112 2016-11-29 16:00  #1323(E6-2. 1st fl.)  Symmetry Protected Kondo Metals and Their Phase Transitions
111 2016-11-24 16:00  #1323(E6-2. 1st fl.)  Harmonic oscillator physics with single atoms in a state-selective optical potential
» 2016-11-18 10:30  #5318(5th fl.)  Non-equilibrium many-body spin dynamics in diamond