Non-equilibrium many-body spin dynamics in diamond
2016.11.17 15:14
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. 최 순 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)
댓글 0
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 |
110 | May 31 (Fri.), 11:00 AM | #1323, E6-2 | Prof. Guido Burkard |
Cavity QED with Spin Qubits
![]() |
109 | May 31 (Tue.) 4 PM | #1323(E6-2, 1st fl.) | Dr. Kimin Kim, KAIST | Understanding 3D tokamak physics towards advanced control of toroidal plasma |
108 | May 311 (Thu.), 04:00 PM | #1323, E6-2 | Prof. Teun-Teun Kim |
Dynamic control of optical properties with gated-graphene metamaterials
![]() |
107 | May. 8th (Wed), 16:00 | E6 Room(#1323) | Jieun Lee |
Imaging valley dependent electron transport in 2D semiconductors
![]() |
106 | May 9 (Thu.), 16:00 PM | #1323, E6-2 | Prof. Kwang Geol Lee |
Quantum Optical Sensing Using Single Photons And Single Photon Emission from Single Emitters
![]() |
105 | May 9 (Thu.), 16:00 PM | #1323, E6-2 | Prof. Kwang Geol Lee |
Quantum Optical Sensing Using Single Photons And Single Photon Emission from Single Emitters
![]() |
104 | May 9 (Wed.), 04:00 PM | #1323, E6-2 | Prof. Jong-Soo Rhyee |
Recent advances in thermoelectric bulk composites
![]() |
103 | May. 11 (Fri.), 02:30 PM | E6-2. 1st fl. #1323 | Dr. Kun Woo Kim |
Disordered Floquet topological insulators
![]() |
102 | May. 11 (Fri.), 04:00 PM | E6-2. 1st fl. #1323 | Dr. Nam Kim |
암페어 단위 재정의와 단전자 펌프 소자 개발
![]() |
101 | May. 12 (Fri.), 01:30 PM | E6-2. 1st fl. #1323 | Dr. Young Kuk Kim | Topological Dirac insulator |
100 | May. 17 (Thu.), 01:30 PM | E6-2. 1st fl. #1323 | Prof. Yong-Baek Kim University of Toronto |
Quantum Spin Liquid in Kitaev Materials
![]() |
99 | May. 3 (Fri), 11:00 AM | E6-2. 2st fl. #2502 | Prof. Changhee Sohn |
Exotic Magnetism
![]() |
98 | May. 8th (Wed), 16:00 | E6 Room(#1323) | Jieun Lee |
Imaging valley dependent electron transport in 2D semiconductors
![]() |
97 | Nov 17th 12:00 PM | Online(Zoom) | Prof. Qiang Lin (Univ. of Rochester, USA) |
Quantum- & Nano-Photonics" 세미나 시리즈
![]() |
96 | Nov. 04 (Fri), 1:30 PM | E6-2. #1323(1st fl.) | Dr. Jonghyun Song, Department of Physics, Chungnam National University | Exotic phenomena at oxide LaAlO3/SrTiO3 hetero-interface and their applications |
95 | Nov. 04 (Fri), 3:00 PM | E6-2. #1323(1st fl.) | Dr. Dohun Kim, Department of Physics and Astronomy, SNU | Quantum information experiments using few electron spins in semiconductors |
94 | Nov. 1 (Fri.), 02:30 PM | E6-2. 1st fl. #1323 | Dr. YoungWook Kim |
Squeezing the best out of 2D materials
![]() |
93 | Nov. 1 (Fri.), 04:00 PM | E6-2. 1st fl. #1323 | Dr. Ju-Jin Kim |
Electron transport through weak-bonded contact metal with low dimensional nano-material
![]() |
92 | Nov. 1 (Tue.) 2:30 pm | Seminar Room #1323(E6-2) | Prof. Youngjoon Kwon, Yonsei Univ. | Search for dark sector particles in the B-factory experiments |
91 | Nov. 10th(Thu) 4 p.m. | E6-2. #1323(1st fl.) | Prof. Min Seok Jang, Electrical Engineering, KAIST | Low Dimensional Active Plasmonics and Electron Optics in Graphene |