0000000000150209

AUTHOR

David Hall

0000-0002-2839-7623

showing 5 related works from this author

Three-dimensional skyrmions in spin-2 Bose–Einstein condensates

2017

We introduce topologically stable three-dimensional skyrmions in the cyclic and biaxial nematic phases of a spin-2 Bose-Einstein condensate. These skyrmions exhibit exceptionally high mapping degrees resulting from the versatile symmetries of the corresponding order parameters. We show how these structures can be created in existing experimental setups and study their temporal evolution and lifetime by numerically solving the three-dimensional Gross-Pitaevskii equations for realistic parameter values. Although the biaxial nematic and cyclic phases are observed to be unstable against transition towards the ferromagnetic phase, their lifetimes are long enough for the skyrmions to be imprinted…

spinor condensateSUPERFLUID HE-3Angular momentumSYMMETRYFOS: Physical sciencesGeneral Physics and AstronomyBose-Einstein condensation114 Physical sciences01 natural sciencesInstability010305 fluids & plasmaslaw.inventionPHASESKNOTSlaw0103 physical sciencesField theory (psychology)magnetismikvanttifysiikka010306 general physicsVORTICESSpin-½Condensed Matter::Quantum GasesPhysicsBose–Einstein condensationBiaxial nematicCondensed matter physicsSkyrmionMONOPOLESCondensed Matter::Mesoscopic Systems and Quantum Hall EffectFIELD-THEORYSymmetry (physics)skyrmionQuantum Gases (cond-mat.quant-gas)Condensed Matter - Quantum GasesBose–Einstein condensateNew Journal of Physics
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Experimental Realization of a Dirac Monopole through the Decay of an Isolated Monopole

2017

We experimentally observe the decay dynamics of deterministically created isolated monopoles in spin-1 Bose-Einstein condensates. As the condensate undergoes a change between magnetic phases, the isolated monopole gradually evolves into a spin configuration hosting a Dirac monopole in its synthetic magnetic field. We characterize in detail the Dirac monopole by measuring the particle densities of the spin states projected along different quantization axes. Importantly, we observe the spontaneous emergence of nodal lines in the condensate density that accompany the Dirac monopole. We also demonstrate that the monopole decay accelerates in weaker magnetic field gradients.

Spin statesmagneetitHigh Energy Physics::LatticeQC1-999Magnetic monopoleFOS: Physical sciencesGeneral Physics and Astronomy01 natural sciences010305 fluids & plasmasQuantization (physics)Atomic and Molecular Physics0103 physical sciences010306 general physicskvanttifysiikkamagnetsSpin-½PhysicsCondensed Matter::Quantum Gasesta114PhysicsMagnetic field gradientMagnetic fieldQuantum Gases (cond-mat.quant-gas)quantum physicsQuantum electrodynamicsParticleCondensed Matter - Quantum GasesRealization (systems)Physical Review X
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Synthetic electromagnetic knot in a three-dimensional skyrmion

2018

We experimentally simulate a quantum-mechanical particle interacting with knotted electromagnetic fields.

Electromagnetic fieldField (physics)skyrmionsQuantum Hall effect01 natural sciences010305 fluids & plasmasElectromagnetism0103 physical sciencesQuantum systemClassical electromagnetismknotted electromagnetic field structureskvanttifysiikka010306 general physicsQuantumResearch ArticlesSpin-½PhysicsMultidisciplinaryta114Physicssähkömagneettiset kentätBose-Einstein condensatesSciAdv r-articlesCondensed Matter PhysicsMathematics::Geometric TopologyClassical mechanicsResearch ArticleScience Advances
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Investigation of long-range female sex pheromone of the European tarnished plant bug, Lygus rugulipennis: chemical, electrophysiological, and field s…

2004

The European tarnished plant bug, Lygus rugulipennis, is an important pest of agricultural and horticultural crops throughout Europe. Adult male L. rugulipennis were previously shown to be attracted to traps baited with live virgin females, which suggests the females produce a sex pheromone. Volatiles produced by virgin female L. rugulipennis were shown to contain three components, hexyl butyrate, (E)-2-hexenyl butyrate, and (E)-4-oxo-2-hexenal which elicited electroantennographic (EAG) responses from males in analyses by linked gas chromatography–electroantennography (GC-EAG). They were produced in 1.5:1:0.08 ratio, respectively, by single females. Collections from 1, 2, or 4 virgin female…

MaleChromatography GasBiologyBiochemistryPheromonesElectroantennographyToxicologyHemipteraSexual Behavior AnimalBotanyAnimalsLygus rugulipennisEcology Evolution Behavior and SystematicsAldehydesDose-Response Relationship DrugHeteropteraGeneral Medicinebiology.organism_classificationMiridaeButyratesSettore AGR/11 - Entomologia Generale E ApplicataSex pheromonePheromoneFemalePEST analysisTarnished plant bugVolatilizationLygus rugulipennis Heteroptera Miridae tarnished plant bug pheromone electroantennography repellence hexyl butyrate (E)-2-hexenyl butyrate (E)-4-oxo-2-hexenalJournal of chemical ecology
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Observation of an Excited $B^{\pm}_c$ Meson State with the ATLAS Detector

2014

A search for excited states of the B±c meson is performed using 4.9 fb-1 of 7 TeV and 19.2 fb-1 of 8 TeV pp collision data collected by the ATLAS experiment at the LHC. A new state is observed through its hadronic transition to the ground state, with the latter detected in the decay B±c→J/ψπ±. The state appears in the m(Bc±π+π-)-m(Bc±)-2m(π±) mass difference distribution with a significance of 5.2 standard deviations. The mass of the observed state is 6842±4±5 MeV, where the first error is statistical and the second is systematic. The mass and decay of this state are consistent with expectations for the second S-wave state of the B±c meson, B±c(2S).

B-C meson; spectroscopy; equationEquationБольшой адронный коллайдер550Atlas detectorlarge hadron colliderGeneral Physics and Astronomyhadronic decay [excited state]7. Clean energy01 natural sciencesHigh Energy Physics - ExperimentSettore FIS/04 - Fisica Nucleare e SubnucleareSubatomär fysikHigh Energy Physics - Experiment (hep-ex)B/c* --> B/c+ pi+ pi-Subatomic Physicsexcited stateddc:550EQUATION[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]scattering [p p]ATLAS Detector; Meson StateB mesonGeneralLiterature_REFERENCE(e.g.dictionariesencyclopediasglossaries)SpectroscopyQCPhysics8000 GeV-cms [7000]Large Hadron ColliderSPECTROSCOPYATLAS experimentSettore FIS/01 - Fisica SperimentaleATLASB-C MESON:Mathematics and natural scienses: 400::Physics: 430::Nuclear and elementary particle physics: 431 [VDP]B/c* --> B/c+ pi+ pi-medicine.anatomical_structureCERN LHC CollExcited statePhysical Sciences7000: 8000 GeV-cmsLHCParticle Physics - ExperimentB-C MesonParticle physicsp p: scatteringMeson530 PhysicsCiências Naturais::Ciências FísicasAstrophysics::High Energy Astrophysical Phenomena:Ciências Físicas [Ciências Naturais]FOS: Physical sciencesmass [excited state]столкновение частиц530hadronic decay [B/c+]Nuclear physicsPhysics and Astronomy (all)(J/psi(3100) pi+) [mass spectrum]B/c+ --> J/psi(3100) pi+Atlas (anatomy)TheoryofComputation_ANALYSISOFALGORITHMSANDPROBLEMCOMPLEXITY0103 physical sciencesmedicineFysikHigh Energy Physics010306 general physicsB/c+ --> J/psi(3100) pi+Ciencias ExactasScience & TechnologyATLAS detector010308 nuclear & particles physicsHigh Energy Physics::Phenomenology:Matematikk og naturvitenskap: 400::Fysikk: 430::Kjerne- og elementærpartikkelfysikk: 431 [VDP]FísicaState (functional analysis)B/c+: hadronic decaymass differencemass spectrum: (J/psi(3100) pi+)B-C MESON; SPECTROSCOPY; EQUATIONB/c+excited state: massexcited state: hadronic decayExperimental High Energy PhysicsмезоныHigh Energy Physics::Experimentproton-proton collisionsATLAS детекторexperimental results
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