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Hassan E, Kessel CE, Park JM, Elwasif WR, Whitfield RE, Kim K, Snyder PB, Batchelor DB, Bernholdt DE, Cianciosa MR, Green DL, Law KJH. Core-Pedestal Plasma Configurations in Advanced Tokamaks. Fusion Science and Technology 2023. [DOI: 10.1080/15361055.2022.2145826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Ehab Hassan
- Oak Ridge National Laboratory, Oak Ridge, Tennessee
- Ain Shams University, Physics Faculty of Science, Cairo, Egypt
| | - C. E. Kessel
- Oak Ridge National Laboratory, Oak Ridge, Tennessee
| | - J. M. Park
- Oak Ridge National Laboratory, Oak Ridge, Tennessee
| | | | | | - K. Kim
- Oak Ridge National Laboratory, Oak Ridge, Tennessee
| | - P. B. Snyder
- Oak Ridge National Laboratory, Oak Ridge, Tennessee
| | | | | | | | - D. L. Green
- Oak Ridge National Laboratory, Oak Ridge, Tennessee
- Commonwealth Scientific and Industrial Research Organization (CSIRO), Sydney, New South Wales, Austalia
| | - K. J. H. Law
- University of Manchester, Department of Mathematics, Manchester, United Kingdom
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Somnath S, Law KJH, Morozovska AN, Maksymovych P, Kim Y, Lu X, Alexe M, Archibald R, Kalinin SV, Jesse S, Vasudevan RK. Ultrafast current imaging by Bayesian inversion. Nat Commun 2018; 9:513. [PMID: 29410417 PMCID: PMC5802759 DOI: 10.1038/s41467-017-02455-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 12/03/2017] [Indexed: 11/25/2022] Open
Abstract
Spectroscopic measurements of current–voltage curves in scanning probe microscopy is the earliest and one of the most common methods for characterizing local energy-dependent electronic properties, providing insight into superconductive, semiconductor, and memristive behaviors. However, the quasistatic nature of these measurements renders them extremely slow. Here, we demonstrate a fundamentally new approach for dynamic spectroscopic current imaging via full information capture and Bayesian inference. This general-mode I–V method allows three orders of magnitude faster measurement rates than presently possible. The technique is demonstrated by acquiring I–V curves in ferroelectric nanocapacitors, yielding >100,000 I–V curves in <20 min. This allows detection of switching currents in the nanoscale capacitors, as well as determination of the dielectric constant. These experiments show the potential for the use of full information capture and Bayesian inference toward extracting physics from rapid I–V measurements, and can be used for transport measurements in both atomic force and scanning tunneling microscopy. Scanning probe microscopy is widely used to characterize material properties with atomic resolution, yet electronic property mapping is normally constrained by slow data acquisition. Somnath et al. show a current–voltage method, which enables fast electronic spectroscopy mapping over micrometer-sized areas.
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Affiliation(s)
- S Somnath
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.,Institute for Functional Imaging of Materials, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - K J H Law
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.,Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - A N Morozovska
- Institute of Physics, National Academy of Sciences of Ukraine, 46, pr. Nauky, Kyiv, 03028, Ukraine
| | - P Maksymovych
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.,Institute for Functional Imaging of Materials, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Y Kim
- School of Advanced Materials Science and Engineering, Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea
| | - X Lu
- The State Key Discipline Laboratory of Wide Band Gap Semiconductor Technology, Xidian University, Xi'an, 710071, Shaanxi, China
| | - M Alexe
- Department of Physics, University of Warwick, Coventry, CV4 7AL, UK
| | - R Archibald
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.,Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - S V Kalinin
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.,Institute for Functional Imaging of Materials, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - S Jesse
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.,Institute for Functional Imaging of Materials, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - R K Vasudevan
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA. .,Institute for Functional Imaging of Materials, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
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Neely TW, Bradley AS, Samson EC, Rooney SJ, Wright EM, Law KJH, Carretero-González R, Kevrekidis PG, Davis MJ, Anderson BP. Characteristics of two-dimensional quantum turbulence in a compressible superfluid. Phys Rev Lett 2013; 111:235301. [PMID: 24476287 DOI: 10.1103/physrevlett.111.235301] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Indexed: 06/03/2023]
Abstract
Fluids subjected to suitable forcing will exhibit turbulence, with characteristics strongly affected by the fluid's physical properties and dimensionality. In this work, we explore two-dimensional (2D) quantum turbulence in an oblate Bose-Einstein condensate confined to an annular trapping potential. Experimentally, we find conditions for which small-scale stirring of the condensate generates disordered 2D vortex distributions that dissipatively evolve toward persistent currents, indicating energy transport from small to large length scales. Simulations of the experiment reveal spontaneous clustering of same-circulation vortices and an incompressible energy spectrum with k(-5/3) dependence for low wave numbers k. This work links experimentally observed vortex dynamics with signatures of 2D turbulence in a compressible superfluid.
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Affiliation(s)
- T W Neely
- College of Optical Sciences, University of Arizona, Tucson, Arizona 85721, USA
| | - A S Bradley
- Jack Dodd Centre for Quantum Technology, Department of Physics, University of Otago, Dunedin 9016, New Zealand
| | - E C Samson
- College of Optical Sciences, University of Arizona, Tucson, Arizona 85721, USA
| | - S J Rooney
- Jack Dodd Centre for Quantum Technology, Department of Physics, University of Otago, Dunedin 9016, New Zealand
| | - E M Wright
- College of Optical Sciences, University of Arizona, Tucson, Arizona 85721, USA
| | - K J H Law
- Mathematics Institute, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - R Carretero-González
- Department of Mathematics and Statistics, San Diego State University, San Diego, California 92182, USA
| | - P G Kevrekidis
- Department of Mathematics and Statistics, University of Massachusetts, Amherst, Massachusetts 01003, USA
| | - M J Davis
- School of Mathematics and Physics, University of Queensland, Brisbane, Queensland 4072, Australia
| | - B P Anderson
- College of Optical Sciences, University of Arizona, Tucson, Arizona 85721, USA
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Law KJH, Kevrekidis PG, Tuckerman LS. Stable vortex-bright-soliton structures in two-component Bose-Einstein condensates. Phys Rev Lett 2010; 105:160405. [PMID: 21230954 DOI: 10.1103/physrevlett.105.160405] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2010] [Indexed: 05/30/2023]
Abstract
We report the numerical realization of robust two-component structures in 2D and 3D Bose-Einstein condensates with nontrivial topological charge in one component. We identify a stable symbiotic state in which a higher-dimensional bright soliton exists even in a homogeneous setting with defocusing interactions, due to the effective potential created by a stable vortex in the other component. The resulting vortex-bright-solitons, generalizations of the recently experimentally observed dark-bright solitons, are found to be very robust both in the homogeneous medium and in the presence of external confinement.
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Affiliation(s)
- K J H Law
- Warwick Mathematics Institute, University of Warwick, Coventry CV4 7AL, United Kingdom
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Wang C, Theocharis G, Kevrekidis PG, Whitaker N, Law KJH, Frantzeskakis DJ, Malomed BA. Two-dimensional paradigm for symmetry breaking: the nonlinear Schrödinger equation with a four-well potential. Phys Rev E Stat Nonlin Soft Matter Phys 2009; 80:046611. [PMID: 19905475 DOI: 10.1103/physreve.80.046611] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2009] [Revised: 08/27/2009] [Indexed: 05/28/2023]
Abstract
We study the existence and stability of localized modes in the two-dimensional (2D) nonlinear Schrödinger/Gross-Pitaevskii (NLS/GP) equation with a symmetric four-well potential. Using the corresponding four-mode approximation, we trace the parametric evolution of the trapped stationary modes, starting from the linear limit, and thus derive a complete bifurcation diagram for families of the stationary modes. This provides the picture of spontaneous symmetry breaking in the fundamental 2D setting. In a broad parameter region, the predictions based on the four-mode decomposition are found to be in good agreement with full numerical solutions of the NLS/GP equation. Stability properties of the stationary states coincide with those suggested by the corresponding discrete model in the large-amplitude limit. The dynamics of unstable modes is explored by means of direct simulations. Finally, in addition to the full analysis for the case of the self-attractive nonlinearity, the bifurcation diagram for the case of self-repulsion is briefly considered too.
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Affiliation(s)
- C Wang
- Department of Mathematics and Statistics, University of Massachusetts, Amherst, Massachusetts 01003-4515, USA
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Law KJH, Kevrekidis PG, Koukouloyannis V, Kourakis I, Frantzeskakis DJ, Bishop AR. Discrete solitons and vortices in hexagonal and honeycomb lattices: existence, stability, and dynamics. Phys Rev E Stat Nonlin Soft Matter Phys 2008; 78:066610. [PMID: 19256971 DOI: 10.1103/physreve.78.066610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2008] [Revised: 10/10/2008] [Indexed: 05/27/2023]
Abstract
We consider a prototypical dynamical lattice model, namely, the discrete nonlinear Schrödinger equation on nonsquare lattice geometries. We present a systematic classification of the solutions that arise in principal six-lattice-site and three-lattice-site contours in the form of both discrete multipole solitons and discrete vortices. Additionally to identifying the possible states, we analytically track their linear stability both qualitatively and quantitatively. We find that among the six-site configurations, the "hexapole" of alternating phases (0-pi) , as well as the vortex of topological charge S=2 have intervals of stability; among three-site states, only the vortex of topological charge S=1 may be stable in the case of focusing nonlinearity. These conclusions are confirmed both for hexagonal and for honeycomb lattices by means of detailed numerical bifurcation analysis of the stationary states from the anticontinuum limit, and by direct simulations to monitor the dynamical instabilities, when the latter arise. The dynamics reveal a wealth of nonlinear behavior resulting not only in single-site solitary wave forms, but also in robust multisite breathing structures.
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Affiliation(s)
- K J H Law
- Department of Mathematics and Statistics, University of Massachusetts, Amherst, Massachusetts 01003-4515, USA
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