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
154 2015-12-03 16:00  E6-2, #1323  Hybrid solid state spin qubits in wide bandgap semiconductors
153 2017-06-02 16:00  #1323 (E6-2. 1st fl.)  Maxwell's demon in quantum wonderland file
152 2022-11-09 16:00  E6-2. 1st fl. #1323  Radio Astronomy, Radio Interferometry, and Multi-wavelength Studies on Relativistic Jets
151 2020-10-15 17:00  https://bit.ly/3ndIiJn  Time crystals, quasicrystals, and time crystal dynamics in the superfluid universe file
150 2022-03-31 10:00  E6 #1501/zoom  Weiss fields for Quantum Spin Dynamics file
149 2022-03-29 10:00  E6 #1501/zoom, E6 #2502/zoom  Non-reciprocal phase transitions file
148 2018-11-09 14:30  E6-2. 1st fl. #1323  Moiré superlattices – from twisted bilayer graphene to quasicrystal file
147 2015-10-16 15:00  E6-2, 5th fl. #5318  High Magnetic Fields to Probe the sub-eV range of Particle/Astroparticle Physics - From the OSQAR experiments at CERN up to new perspectives at LNCMI-Grenoble
146 2018-07-02 15:00  Seminar Room (C303), Creation Hall (3F), KAIST Munji Campus  High Precision Magnetic Field Measurement for the Muon g-2 Experiment file
145 2016-06-01 10:30  BK21 Conference Room (#1318, E6-2)  Welcome to Nature Photonics
144 2018-05-11 16:00  E6-2. 1st fl. #1323  암페어 단위 재정의와 단전자 펌프 소자 개발 file
143 2016-04-26 16:00  #1323(1st Floor. E6-2)  Transport spectroscopy for electronic bands in carbon-based nanomaterials with weak-bond contacts
142 2022-08-12 10:00  E6-1 #1323  Twisted Bilayer Magnets file
141 2022-08-12 10:00  E6-1 #1323  Twisted Bilayer Magnets file
140 2022-10-06 13:00  E6 #1323  Counting States with Global Symmetry
139 2019-06-12 15:00  Rm# 1323, E6-2  The relation between free and interacting fermionic SPT phases file
138 2016-09-29 16:00  E6-2. #2501(2nd fl.)  Exploring the phase diagram of BaBiO3: epic voyage of just another bad trip?
137 2017-04-28 16:00  #1323 (E6-2. 1st fl.)  Carbon nanotubes coupled to superconducting impedance matching circuits
136 2019-07-30 16:00  #1323, E6-2  Dirac fermions and flat bands in correlated kagome metals file
135 2017-11-03 14:30  #1323 (1st fl., E6-2.)  Quantum Resistor-Capacitor Circuit with Majorana Edge States file