visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나
날짜 2016-11-18 10:30 
연사  
장소 #5318(5th fl.) 

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 연사 제목
공지 2025-02-24 16:00    2025년 봄학기 콜로키움 안내
공지 2025-02-27 16:00    2025년 봄 물리학과 특별세미나 (광학/응집물리 분야)
574 2025-01-08 16:00  Dr. SangEun Han  Quantum impurity model for two-stage multipolar ordering and Fermi surface reconstruction
573 2024-12-17 15:00  Isaac H. Kim  Learning state preparation circuit for quantum phases of matter (Isaac H. Kim, UC Davis)
572 2024-12-06 16:00  Vladimir Y. Chernyak  Bright Squeezed Light (BSL) Spectroscopy with Interferometry from First Principles
571 2024-11-30 10:30  Joon Young Park  Towards probing topological phases in Corbino-geometry Josephson junctions on a topological insulator surface
570 2024-11-21 16:00  Prof. Ulrich Höfer  Time-resolved photoemission: From bandstructure to orbital movies file
569 2024-11-21 11:00  Daniel L. Jafferis  3d Gravity and Tensor Model file
568 2024-11-18 10:30    Manipulation of antiferromagnetic magnon polarization in synthetic antiferromagnets
567 2024-11-13 12:00    [11/13(수) 물리학과 세미나 안내] Separability as a window to mixed-state quantum phases and phase transitions / Tarun Grover (UC San Diego, Associate Professor)
566 2024-10-31 13:00    Mini-workshop on first-principles DFT methods and applications
565 2024-10-30 14:30    [Seminar Invitation] Mario Cuoco (CNR-SPIN, c/o University of Salerno, Fisciano, Italy) / 2024.10.30. 14:30 / E6-2, #3441
564 2024-10-21 13:00    [Physics Seminar] “Non-Hermitian Point-Gap Topology in Junction Systems” file
563 2024-10-17 16:00    Photonic Methods for Quantum Levitodynamics Beyond the Rayleigh Regime
562 2024-10-14 11:00    [RSVP, Oct 14th Mon] Ambassador of Hungary to Republic of Korea Special Lecture file
561 2024-10-02 12:00    Data-driven discovery of neural computations through brain-wide and cell-type-specific dynamical systems file
560 2024-09-26 14:00    Quantum spin nematic phase in a square-lattice iridate
559 2024-09-03 12:00    2024 가을학기 물리학과 특별세미나 전체 일정 (응집물리 및 광학분야) file
558 2024-09-02 16:00    2024학년도 가을학기 물리학과 콜로키움(Physics Colloquium) file
557 2024-08-22 16:00    [CAPP seminar] Development of a 12-20 GHz CO Intensity Mapping Receiver for Capturing the Star-formation History in the Early Universe file
556 2024-08-16 11:00    Cathodoluminescence for nanophotonics: Applications to plasmonic bandgap materials and perovskite semiconductors file
555 2024-08-14 11:00    Pair Density Waves and Supercurrent Diode Effect in Altermagnets