visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나
장소 #5318(5th fl.) 
일시 Nov. 18th (Fri) 10:30 a.m. 
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 일시 장소 연사 제목
공지 2019/09/18 - 12/5  Seminar Room #1323  Prof. David Schuster and etc.  Fall 2019: Physics Seminar Serises
공지 2019/09/02 - 12/09  Seminar Room 1501  이호성 박사 (한국표준과학연구원) and etc.  Fall 2019: Physics Colloquium
178 Nov. 3 (Fri.), 2:30 PM  #1323 (1st fl., E6-2.)  Dr. MinChul Lee(Department of Applied Physics, Kyung Hee Univ.)  Quantum Resistor-Capacitor Circuit with Majorana Edge States file
177 July 30 (Tue), 4:00 PM  #1323, E6-2  Dr. Mingu Kang  Dirac fermions and flat bands in correlated kagome metals file
176 Apr. 28 (Fri.), 04:00 PM  #1323 (E6-2. 1st fl.)  Dr. Minkyung Jung Research Institute, DGIST  Carbon nanotubes coupled to superconducting impedance matching circuits
175 Sep. 29 (Thu), 4:00 PM  E6-2. #2501(2nd fl.)  Dr. Minu Kim, Institute for Basic Science, Seoul National University  Exploring the phase diagram of BaBiO3: epic voyage of just another bad trip?
174 3 PM, 12 Jun (Wed), 2019  Rm# 1323, E6-2  Dr. Minyoung You  The relation between free and interacting fermionic SPT phases file
173 April 26 (Tue), 4PM  #1323(1st Floor. E6-2)  Dr. Myung-Ho Bae, Korea Research Institute of Standards and Science  Transport spectroscopy for electronic bands in carbon-based nanomaterials with weak-bond contacts
172 May. 11 (Fri.), 04:00 PM  E6-2. 1st fl. #1323  Dr. Nam Kim  암페어 단위 재정의와 단전자 펌프 소자 개발 file
171 Jun. 1(Wed) 10:30 AM  BK21 Conference Room (#1318, E6-2)  Dr. Noriaki Horiuchi, Editor, Nature Photonics  Welcome to Nature Photonics
170 July 2. 2018 (Monday) 3:00 PM  Seminar Room (C303), Creation Hall (3F), KAIST Munji Campus  Dr. Peter Winter (Argonne National Laboratory)  High Precision Magnetic Field Measurement for the Muon g-2 Experiment file
169 2015/10/16, 3PM  E6-2, 5th fl. #5318  Dr. Pierre Pugnat , (CNRS-LNCMI)  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
168 Nov. 9 (Fri.), 02:30 PM  E6-2. 1st fl. #1323  Dr. Pilkyung Moon  Moiré superlattices – from twisted bilayer graphene to quasicrystal file
167 Jun. 2 (Fri.), 4:00 PM  #1323 (E6-2. 1st fl.)  Dr. Sang Wook Kim  Maxwell's demon in quantum wonderland file
166 2015/12/03, 4PM  E6-2, #1323  Dr. Sang-Yun Lee (3rd institute of Physics, University of Stuttgart, Germany)  Hybrid solid state spin qubits in wide bandgap semiconductors
165 Mar. 24 (Fri.), 4:00 PM  #1323 (1st fl. E6-2)  Dr. SangWook Lee  Graphene based nano electronics and nano electromechanics; focusing on precise control of nano structures for studying accurate physical properties
164 Sep. 29th(Thu), 4PM  E6-2 #1323 (1st floor)  Dr. Sangyoon Han, Department of Physics, KAIST  Large-scale Silicon Photonic MEMS Switches
163 2015/07/15, 2PM  E6-2,1323  Dr. Se Young Park(Rutgers Univ.)  Electronic and optical properties of titanate-based oxide superlattices
162 June 17 (Mon.), 10:30 AM  #1323, E6-2  Dr. See-Hun Yang  Chiral Spintronics file
161 Apr. 19 (Fri.), 04:00 PM  E6-2. 1st fl. #1323  Dr. Seok Kyun Son  Graphene and hBN heterostructures file
160 2016/1/26, 2PM  E6-2, #1323  Dr. Sergei V. Kalinin (Center for Nanophase Materials Sciences, Oak Ridge National Laboratory)  Electrochemistry on Nano- and Atomic Levels: Scanning Probe Microscopy Meets Deep Data
159 Mar. 29 (Fri.), 02:30 PM  E6-2. 1st fl. #1323  Dr. Seung Hyub Baek  Epitaxial Multifunctional Oxide Thin Films for Novel Electronics file