Journal of Physics B: Atomic, Molecular and Optical Physics最新文献

{"title":"Vector gap solitons of spin-orbit-coupled Bose-Einstein condensate in square optical lattice","authors":"Qingqing Wang, Pu Tu, Jinping Ma, Kaihua Shao, Xi Zhao, Baolong Xi, Yan Song, Yuren Shi","doi":"10.1088/1361-6455/ad2e2c","DOIUrl":"https://doi.org/10.1088/1361-6455/ad2e2c","url":null,"abstract":"Vector gap solitons in quasi-two-dimensional Bose–Einstein condensate loaded in a square optical lattice with spin-orbit and Rabi coupling are investigated theoretically. The solitons are obtained by the Newton-Conjugate-Gradient method for various physical parameters. The stability properties of gap solitons are theoretically analyzed by direct nonlinear dynamical evolution. It is found that the existence of gap solitons is sensitive to the spin-orbit and Rabi coupling strength. Smaller Rabi coupling strength is beneficial for the excitation of solitons in the semi-infinite gap. Conversely, larger Rabi coupling strength is beneficial for the soliton excitation in the first gap. The dynamical stability of these gap solitons depends on the spin-orbit and Rabi coupling strength, and the location of the soliton in the bandgap. These findings may contribute to understanding the topological excitations in condensed matter systems.","PeriodicalId":16826,"journal":{"name":"Journal of Physics B: Atomic, Molecular and Optical Physics","volume":"15 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140316078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Convolutional neural network for retrieval of the time-dependent bond length in a molecule from photoelectron momentum distributions","authors":"N I Shvetsov-Shilovski, M Lein","doi":"10.1088/1361-6455/ad2e30","DOIUrl":"https://doi.org/10.1088/1361-6455/ad2e30","url":null,"abstract":"We apply deep learning for retrieval of the time-dependent bond length in the dissociating two-dimensional H<inline-formula>\u0000<tex-math><?CDATA $_2^{+}$?></tex-math>\u0000<mml:math overflow=\"scroll\"><mml:msubsup><mml:mi></mml:mi><mml:mn>2</mml:mn><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msubsup></mml:math>\u0000<inline-graphic xlink:href=\"bad2e30ieqn1.gif\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> molecule using photoelectron momentum distributions. We consider a pump-probe scheme and calculate electron momentum distributions from strong-field ionization by treating the motion of the nuclei classically, semiclassically or quantum mechanically. A convolutional neural network trained on momentum distributions obtained at fixed internuclear distances retrieves the time-varying bond length with an absolute error of 0.2–0.3 a.u.","PeriodicalId":16826,"journal":{"name":"Journal of Physics B: Atomic, Molecular and Optical Physics","volume":"44 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140316087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Targeted optimization in small-scale atomic structure calculations: application to Au I","authors":"Sema Caliskan, Jon Grumer, Anish M Amarsi","doi":"10.1088/1361-6455/ad2b71","DOIUrl":"https://doi.org/10.1088/1361-6455/ad2b71","url":null,"abstract":"The lack of reliable atomic data can be a severe limitation in astrophysical modelling, in particular of events such as kilonovae that require information on all neutron-capture elements across a wide range of ionization stages. Notably, the presence of non-orthonormalities between electron orbitals representing configurations that are close in energy can introduce significant inaccuracies in computed energies and transition probabilities. Here, we propose an explicit targeted optimization (TO) method that can effectively circumvent this concern while retaining an orthonormal orbital basis set. We illustrate this method within the framework of small-scale atomic structure models of Au I, using the <sc>Grasp2018</sc> multiconfigurational Dirac–Hartree–Fock atomic structure code. By comparing to conventional optimization schemes we show how a TO approach improves the energy level positioning and ordering. TO also leads to better agreement with experimental data for the strongest E1 transitions. This illustrates how small-scale models can be significantly improved with minor computational costs if orbital non-orthonormalities are considered carefully. These results should prove useful to multi-element atomic structure calculations in, for example, astrophysical opacity applications involving neutron-capture elements.","PeriodicalId":16826,"journal":{"name":"Journal of Physics B: Atomic, Molecular and Optical Physics","volume":"216 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140316232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measurement of steep dispersion associated with magnetically assisted gain in Zeeman degenerate two-level system of cold atoms","authors":"J C de Aquino Carvalho, R S N Moreira, J W R Tabosa","doi":"10.1088/1361-6455/ad2b6f","DOIUrl":"https://doi.org/10.1088/1361-6455/ad2b6f","url":null,"abstract":"We report on the measurements of magnetically assisted dispersion and gain in a Zeeman degenerate two-level system associated with the closed <italic toggle=\"yes\">D</italic>\u0000₂ hyperfine transition <inline-formula>\u0000<tex-math><?CDATA $F_mathrm{g} = 3 rightarrow F_mathrm{e} = 2$?></tex-math>\u0000<mml:math overflow=\"scroll\"><mml:msub><mml:mi>F</mml:mi><mml:mrow><mml:mi mathvariant=\"normal\">g</mml:mi></mml:mrow></mml:msub><mml:mo>=</mml:mo><mml:mn>3</mml:mn><mml:mo stretchy=\"false\">→</mml:mo><mml:msub><mml:mi>F</mml:mi><mml:mrow><mml:mi mathvariant=\"normal\">e</mml:mi></mml:mrow></mml:msub><mml:mo>=</mml:mo><mml:mn>2</mml:mn></mml:math>\u0000<inline-graphic xlink:href=\"bad2b6fieqn1.gif\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> cold cesium atoms. We use a Mach–Zehnder interferometer to measure the dispersive properties of this system in the presence of a magnetic field, transversal to the quantization direction, when the atomic system is excited by a coupling and probe beams with orthogonal polarizations. We have measured the spectrum of the refraction index for different magnitudes of the external magnetic field and different coupling beam intensities. A previously published theoretical model, using a simpler atomic transition <inline-formula>\u0000<tex-math><?CDATA $F_mathrm{g} = 1 rightarrow F_mathrm{e} = 0$?></tex-math>\u0000<mml:math overflow=\"scroll\"><mml:msub><mml:mi>F</mml:mi><mml:mrow><mml:mi mathvariant=\"normal\">g</mml:mi></mml:mrow></mml:msub><mml:mo>=</mml:mo><mml:mn>1</mml:mn><mml:mo stretchy=\"false\">→</mml:mo><mml:msub><mml:mi>F</mml:mi><mml:mrow><mml:mi mathvariant=\"normal\">e</mml:mi></mml:mrow></mml:msub><mml:mo>=</mml:mo><mml:mn>0</mml:mn></mml:math>\u0000<inline-graphic xlink:href=\"bad2b6fieqn2.gif\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula>, accounts reasonably for the experimentally observed gain and dispersive lineshapes.","PeriodicalId":16826,"journal":{"name":"Journal of Physics B: Atomic, Molecular and Optical Physics","volume":"62 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140316252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"L-Mn dielectronic recombination of cerium ions in a room-temperature EBIT","authors":"W Biela-Nowaczyk, F Grilo, P Amaro, A Warczak","doi":"10.1088/1361-6455/ad2b72","DOIUrl":"https://doi.org/10.1088/1361-6455/ad2b72","url":null,"abstract":"We explore the dielectronic recombination structures at the electron beam ion trap at Jagiellonian University in Cracow, emited by cerium that is produced by the high-current cathode made of iridium and cerium. Small amounts of these elements evaporate from the cathode and form low-intensity admixtures within the electron-ion plasma in the EBIT. Their presence and specific ionic population can be observed by examining the spectral characteristics resulting from the DR process. Results have been compared with flexible atomic code calculations, working in unresolved transition array mode, providing identification of the charge states. Here we show that this mode provides quick calculations of very complex data with enough reliability for experimental comparison. These observations highlight which DR features and corresponding charge states that should be present in spectra obtained in EBITs with similar cathode specifications.","PeriodicalId":16826,"journal":{"name":"Journal of Physics B: Atomic, Molecular and Optical Physics","volume":"63 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140316092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Competition of multiphoton ionization pathways in lithium","authors":"Balázs Tóth, Attila Tóth, András Csehi","doi":"10.1088/1361-6455/ad2b73","DOIUrl":"https://doi.org/10.1088/1361-6455/ad2b73","url":null,"abstract":"We study the three-photon ionization of atomic lithium by intense, short light pulses, via numerically solving the time-dependent Schrödinger equation. Two-photon Rabi oscillations are induced between the 2<italic toggle=\"yes\">s</italic> and 4<italic toggle=\"yes\">s</italic> states, which are damped due to single-photon ionization to the <italic toggle=\"yes\">p</italic> continuum. Developing a minimal three-level model, we analyze the spectral features of the Autler–Townes (AT) doublet that is formed upon the resonant coupling with the laser pulse. Furthermore, we show that this <inline-formula>\u0000<tex-math><?CDATA $2s rightarrow rightarrow 4s rightarrow p~continuum$?></tex-math>\u0000<mml:math overflow=\"scroll\"><mml:mn>2</mml:mn><mml:mi>s</mml:mi><mml:mo stretchy=\"false\">→→</mml:mo><mml:mn>4</mml:mn><mml:mi>s</mml:mi><mml:mo stretchy=\"false\">→</mml:mo><mml:mi>p</mml:mi><mml:mtext> </mml:mtext><mml:mi>c</mml:mi><mml:mi>o</mml:mi><mml:mi>n</mml:mi><mml:mi>t</mml:mi><mml:mi>i</mml:mi><mml:mi>n</mml:mi><mml:mi>u</mml:mi><mml:mi>u</mml:mi><mml:mi>m</mml:mi></mml:math>\u0000<inline-graphic xlink:href=\"bad2b73ieqn1.gif\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> pathway is the dominant process, if the duration of the laser pulse exceeds a certain value. For shorter pulses, ionization through the 2<italic toggle=\"yes\">p</italic> state (<inline-formula>\u0000<tex-math><?CDATA $2s rightarrow 2p rightarrow 4d rightarrow f~continuum$?></tex-math>\u0000<mml:math overflow=\"scroll\"><mml:mn>2</mml:mn><mml:mi>s</mml:mi><mml:mo stretchy=\"false\">→</mml:mo><mml:mn>2</mml:mn><mml:mi>p</mml:mi><mml:mo stretchy=\"false\">→</mml:mo><mml:mn>4</mml:mn><mml:mi>d</mml:mi><mml:mo stretchy=\"false\">→</mml:mo><mml:mi>f</mml:mi><mml:mtext> </mml:mtext><mml:mi>c</mml:mi><mml:mi>o</mml:mi><mml:mi>n</mml:mi><mml:mi>t</mml:mi><mml:mi>i</mml:mi><mml:mi>n</mml:mi><mml:mi>u</mml:mi><mml:mi>u</mml:mi><mml:mi>m</mml:mi></mml:math>\u0000<inline-graphic xlink:href=\"bad2b73ieqn2.gif\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula>) gradually becomes the dominant process, provided that the pulse is strong enough to induce several Rabi floppings. Here, we trace the competition of these ionization pathways by observing the structural changes in the shape of the AT doublet.","PeriodicalId":16826,"journal":{"name":"Journal of Physics B: Atomic, Molecular and Optical Physics","volume":"199 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140316188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Azimuthal phase-dependent electromagnetically induced transparency and the generation of spatial light in a microwave-assisted four-level Y-type system","authors":"Samim Akhtar, Jayanta K Saha, Md Mabud Hossain","doi":"10.1088/1361-6455/ad2b70","DOIUrl":"https://doi.org/10.1088/1361-6455/ad2b70","url":null,"abstract":"We present an azimuthal phase-dependent scheme to study the spatially dependent electromagnetically induced transparency (EIT) and the generation of spatial light in a closed-loop four-level Y-type system. A structured control beam and a microwave (MW) field are adopted in the closed-loop structure. Interestingly, the weak non-vortex probe beam responses explicitly depend on the orbital angular momentum (OAM) of the control beam along with the MW-assisted quantum interference. The regions of spatially dependent EIT are demonstrated at different azimuthal angles. It is found that the intensity of the structured control beam and the relative phase arising out of the beams participating in the closed-loop can be used as the controlling knobs to tailor the shape and the angular location of the spatially dependent EIT.","PeriodicalId":16826,"journal":{"name":"Journal of Physics B: Atomic, Molecular and Optical Physics","volume":"44 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140316074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantum degeneracy and spin entanglement in ideal quantum gases","authors":"Fatma Zouari Ahmed, Mohammed Tayeb Meftah, Tommaso Roscilde","doi":"10.1088/1361-6455/ad2861","DOIUrl":"https://doi.org/10.1088/1361-6455/ad2861","url":null,"abstract":"Quantum degeneracy is the central many-body feature of ideal quantum gases stemming from quantum mechanics. In this work we address its relationship to the most fundamental form of non-classicality in many-body system, i.e. many-body entanglement. We aim at establishing a quantitative link between quantum degeneracy and entanglement in spinful ideal gases, using entanglement witness criteria based on the variance of the collective spin of the spin ensemble. We show that spin-1/2 ideal Bose gases do not possess entanglement which can be revealed from such entanglement criteria. On the contrary, ideal spin-1/2 Fermi gases exhibit spin entanglement revealed by the collective-spin variances upon entering quantum degeneracy, due to the formation of highly non-local spin singlets. We map out the regime of detectable spin entanglement for Fermi gases in free space as well as in a parabolic trap, and probe the robustness of spin entanglement to thermal effects and spin imbalance. Spin entanglement in degenerate Fermi gases is amenable to experimental observation using state-of-the-art spin detection techniques in ultracold atoms.","PeriodicalId":16826,"journal":{"name":"Journal of Physics B: Atomic, Molecular and Optical Physics","volume":"45 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140006055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Production of twisted particles in magnetic fields","authors":"Liping Zou, Pengming Zhang, Alexander J Silenko","doi":"10.1088/1361-6455/ad23f7","DOIUrl":"https://doi.org/10.1088/1361-6455/ad23f7","url":null,"abstract":"The use of a (quasi)uniform magnetic field opens new possibilities for the production of twisted particles having orbital angular momenta. We ascertain these possibilities. Quantum states suitable for the creation of charged particles in a uniform magnetic field are determined. The particle penetration from a solenoid to vacuum or another solenoid is analyzed in detail. It is shown that a previously proposed approach can be utilized for the successful production of twisted positrons and positroniums. We also find a new effect of increasing the uncertainty of the phase of the particle rotation with the distance passed by the particle in the solenoid. This effect, based on the fundamentals of quantum mechanics, leads to exciting new possibilities for the production of twisted particles in real solenoids without additional particle sources therein.","PeriodicalId":16826,"journal":{"name":"Journal of Physics B: Atomic, Molecular and Optical Physics","volume":"79 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140006081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum: Exploring the role of beyond mean-field interaction in the structure and dynamics of one-dimensional quantum droplets (2023 J. Phys. B: At. Mol. Opt. Phys. 56 165302)","authors":"Sonali Gangwar, Rajamanickam Ravisankar, Paulsamy Muruganandam, Pankaj Kumar Mishra","doi":"10.1088/1361-6455/ad2549","DOIUrl":"https://doi.org/10.1088/1361-6455/ad2549","url":null,"abstract":"In our recent paper (Gangwar <italic toggle=\"yes\">et al</italic> 2023 <italic toggle=\"yes\">J. Phys. B: At. Mol. Opt. Phys.</italic>\u0000<bold>56</bold> 165302), we noticed a minor mistake in equations (1) and (2). In this corrigendum, we provide the corrected equations and necessary modified figures. However, overall results and conclusions of our original paper remain unchanged.","PeriodicalId":16826,"journal":{"name":"Journal of Physics B: Atomic, Molecular and Optical Physics","volume":"79 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140006064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}