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

{"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}

{"title":"Classical-trajectory model for ionizing proton-ammonia molecule collisions: the role of multiple ionization","authors":"Alba Jorge, Marko Horbatsch, Tom Kirchner","doi":"10.1088/1361-6455/ad285c","DOIUrl":"https://doi.org/10.1088/1361-6455/ad285c","url":null,"abstract":"We use an independent electron model with semi-classical approximation to electron dynamics to investigate differential cross sections for electron emission in fast collisions of protons with ammonia molecules. An effective potential model for the electronic orbitals is introduced, and utilized in the context of the classical-trajectory Monte Carlo (CTMC) approach for single-electron dynamics. Cross sections differential in electron emission angle and energy are compared with experimental data. Compared to previous scattering-theory based quantum-mechanical results the time-dependent semi-classical CTMC approach provides results of similar quality for intermediate and high ionized electron energies. We find some discrepancies in the total cross sections for <italic toggle=\"yes\">q</italic>-fold ionization between the present model and independent-atom-model calculations. The double ionization cross sections are considerably larger than recent experimental data which are derived from coincidence counting of charged fragments. The calculated triple ionization cross sections exceed the experimental coincidence data for <italic toggle=\"yes\">q</italic> = 3 by several orders of magnitude at intermediate energies.","PeriodicalId":16826,"journal":{"name":"Journal of Physics B: Atomic, Molecular and Optical Physics","volume":"45 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140005851","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":"Two-center resonant photoionization-excitation driven by combined intra- and interatomic electron correlations","authors":"S Kim, S Steinhäuser, A B Voitkiv, C Müller","doi":"10.1088/1361-6455/ad23f6","DOIUrl":"https://doi.org/10.1088/1361-6455/ad23f6","url":null,"abstract":"Ionization-excitation of an atom induced by the absorption of a single photon in the presence of a neighboring atom is studied. The latter is, first, resonantly photoexcited and, afterwards, transfers the excitation energy radiationlessly to the other atom, leading to its ionization with simultaneous excitation. The process relies on the combined effects of interatomic and intraatomic electron correlations. Under suitable conditions, it can dominate by several orders of magnitude over direct photoionization-excitation and even over direct photoionization. In addition, we briefly discuss another kind of two-center resonant photoionization with excitation where the ionization and residual excitation in the final state are located at different atomic sites.","PeriodicalId":16826,"journal":{"name":"Journal of Physics B: Atomic, Molecular and Optical Physics","volume":"308 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139769993","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":"Propagation properties and stability of dark solitons in weakly interacting Bose–Bose droplets","authors":"Jakub Kopyciński, Buğra Tüzemen, Wojciech Górecki, Krzysztof Pawłowski, Maciej Łebek","doi":"10.1088/1361-6455/ad2546","DOIUrl":"https://doi.org/10.1088/1361-6455/ad2546","url":null,"abstract":"We investigate dark solitons in two-component Bose systems with competing interactions in one dimension. Such a system hosts a liquid phase stabilized by the beyond-mean field corrections. Using the generalized Gross–Pitaevskii equation, we reveal the presence of two families of solitonic solutions. The solitons in both of them can be engineered to be arbitrarily wide. One family of solutions, however, has an anomalous dispersion relation, and our analyses show one of its branches is unstable. We find a critical velocity that demarcates the stable from unstable solutions. Nonetheless, gray anomalous solitons can exist inside quantum droplets and can be treated as solitonic excitations thereof.","PeriodicalId":16826,"journal":{"name":"Journal of Physics B: Atomic, Molecular and Optical Physics","volume":"5 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139769999","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}