Jie Yan, Guanpeng Yan, Fengtao Jin, Yongjun Li, Cheng Gao, Jiaolong Zeng and Jianmin Yuan
{"title":"Evolution of level population in Ar interacting with XFEL pulses: impact of resonant absorptions","authors":"Jie Yan, Guanpeng Yan, Fengtao Jin, Yongjun Li, Cheng Gao, Jiaolong Zeng and Jianmin Yuan","doi":"10.1088/1361-6455/ad5ee5","DOIUrl":"https://doi.org/10.1088/1361-6455/ad5ee5","url":null,"abstract":"Theoretical exploration of the population dynamics at fine-structure levels of Ar atoms interacting with ultrafast ultraintense x-ray free electron laser (XFEL) pulses is conducted. A time-dependent rate equation based on a detailed-level accounting approach is applied for tracking population levels, encompassing microscopic atomic processes such as photoexcitation, radiative decay, photoionization and Auger decay. A Monte Carlo algorithm is implemented to solve large-scale rate equations efficiently. The primary investigation centers on generating Ar17+ through resonant absorption by the second-harmonic radiation of the x-ray pulse. The calculated population ratios of Ar17+ to Ar16+ align well with the experimental measurements (LaForge et al 2021 Phys. Rev. Lett.127 213202). In comparison to the transition energy of the strongest line, of Ar16+, there is a distinct ∼25 eV red shift in the peak ratio, which is attributed to the presence of intricate resonant channels in the lower ionization stages. The results demonstrate the sensitivity of the population ratio Ar17+/Ar16+ to the laser pulse parameters such as x-ray pulse duration, bandwidth and the contribution of second-harmonic radiation, indicating their potential as diagnostic tools in future experiments.","PeriodicalId":16826,"journal":{"name":"Journal of Physics B: Atomic, Molecular and Optical Physics","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141585122","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}
Anwesha Panda, Sneha Dey, Yogishree Arabinda Panda, Aditya Anurag Dash, Aloke Jana and Nirmalya Ghosh
{"title":"Influence of orbital angular momentum of light on random spin-split modes in disordered anisotropic optical media","authors":"Anwesha Panda, Sneha Dey, Yogishree Arabinda Panda, Aditya Anurag Dash, Aloke Jana and Nirmalya Ghosh","doi":"10.1088/1361-6455/ad5e21","DOIUrl":"https://doi.org/10.1088/1361-6455/ad5e21","url":null,"abstract":"Spin–orbit interaction of light in a disordered anisotropic medium is known to yield spin split modes in the momentum domain because of the random spatial gradient of the geometric phase of light. Here, we have studied the statistics of such spin-split modes for beams carrying intrinsic orbital angular momentum through the quantification of momentum domain entropy and investigated its dependence on various beam parameters. The influence of the spatial structure of the beam and the phase vortex on the statistics of the spin split modes were separately investigated using input Laguerre–Gaussian and Perfect Vortex beams passing through a disordered anisotropic medium with controlled input disorder parameter, which was realized by modulating the pixels of a liquid crystal-based spatial light modulator. The results of systematic investigations on the impact of beam waist, spot size and topological charge of the vortex beam show that the influence of the spot size on the emergence of the random spin split modes is much more significant as compared to the other beam parameters.","PeriodicalId":16826,"journal":{"name":"Journal of Physics B: Atomic, Molecular and Optical Physics","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141570056","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":"Avoiding lateral mode leakage in thin film lithium niobate waveguides for the generation of spectrally pure photons at telecom wavelengths","authors":"Muskan Arora, Pranav Chokkara, Jasleen Lugani","doi":"10.1088/1361-6455/ad5c3e","DOIUrl":"https://doi.org/10.1088/1361-6455/ad5c3e","url":null,"abstract":"Photonic integrated optical components, notably straight waveguides, serve as pivotal elements for on-chip generation and manipulation of quantum states of light. In this work, we focus on optimizing waveguides based on lithium niobate on insulator (LNOI) to generate photon pairs at telecom wavelengths using spontaneous parametric down-conversion (SPDC). Specifically, we investigate lateral leakage for all possible SPDC processes involving type 0, type I, and type II phase matching conditions in an X-cut lithium niobate waveguide and provide a recipe to avoid leakage loss for the interacting photons. Furthermore, focusing on type II phase matching, we engineer the waveguide in the single-mode regime such that it also satisfies group index matching for generating spectrally pure single photons with high purity (99.33%). We also address fabrication imperfections of the optimized design and find that the spectral purity of the generated photons is robust to fabrication errors. This work offers guidance for the suitable selection of morphological parameters to obtain lossless, single-mode LNOI waveguides for building linear optical circuits and photon pair generation at telecom wavelengths using desired phase-matching conditions.","PeriodicalId":16826,"journal":{"name":"Journal of Physics B: Atomic, Molecular and Optical Physics","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141570057","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":"Information-theoretic measures and Compton profile of H atom under finite oscillator potential","authors":"S. Mondal, A. Sadhukhan, J. K. Saha, A. K. Roy","doi":"10.1088/1361-6455/ad5fd3","DOIUrl":"https://doi.org/10.1088/1361-6455/ad5fd3","url":null,"abstract":"\u0000 Information-theoretic measures for $nl~(^2L)$ states of H atom (with $n=1-10$ and $l=0-2$, where $n$ and $l$ denote principal and angular momentum quantum numbers) have been investigated within a quantum dot by utilizing the Ritz variational principle, with the help of a Slater-type basis set. A well-established two-parameter (depth and width) model finite oscillator potential is used to simulate the dot environment. Variationally optimized position ($r$)-space wave function is utilized to determine the momentum ($p$)-space wave function, leading to the generation of $p$-space radial density distribution. We have explored the impact of cavity parameters on quantum information theoretic measures, such as Shannon ($S$) and Fisher information ($I$) entropy, in ground as well as excited states. The results of $S$ were also used to test the Bialynicki-Birula-Mycielski (BBM) inequality, related to the entropic uncertainty principle for the confined H atom. Some simple new fitting laws pertaining to $S$ and $I$ have been proposed. Furthermore, the $p$-space radial density is employed to derive the Compton profile of the confined H atom. Possible tunability of $S, I$ and Compton profiles with respect to the parameters are noted.","PeriodicalId":16826,"journal":{"name":"Journal of Physics B: Atomic, Molecular and Optical Physics","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141675581","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}
Kensei Kitajima, Takuya Majima and Hidetsugu Tsuchida
{"title":"Mass spectrometric study of fast heavy-ion induced products on microdroplet surfaces","authors":"Kensei Kitajima, Takuya Majima and Hidetsugu Tsuchida","doi":"10.1088/1361-6455/ad31ae","DOIUrl":"https://doi.org/10.1088/1361-6455/ad31ae","url":null,"abstract":"Fast heavy-ion collisions with molecules that constitute a liquid are fundamental to the field of radiation chemistry and its application to biology. However, although collision-induced physical and chemical processes in liquids have been extensively studied, the initial stages of such processes remain not fully understood because of their complex behaviors. Accordingly, our group has studied the initial reactions occurring in the vicinity of fast-ion trajectories in liquids by mass spectrometric analysis of the secondary ions ejected from microdroplet surfaces upon fast heavy-ion impacts. In this topical review, we present our recent experimental advances in secondary-ion mass spectrometry using microdroplets of water, alcohols, and amino acid solutions. Our findings demonstrate the complex physicochemical behaviors of positive and negative product ions and highlight the role of secondary electrons in the mechanisms of biomolecular damage triggered by fast heavy ions.","PeriodicalId":16826,"journal":{"name":"Journal of Physics B: Atomic, Molecular and Optical Physics","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141551949","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 dynamics of multipole solitons generated in dissipative systems","authors":"Haowen Wang, Jianjun Wen, Yan Xiao","doi":"10.1088/1361-6455/ad5ee4","DOIUrl":"https://doi.org/10.1088/1361-6455/ad5ee4","url":null,"abstract":"\u0000 The propagation dynamics of multipole solitons generated in dissipative systems are investigated numerically based on the fractional complex cubic-quintic Ginzburg-Landau equation using the Airy beam as the input beam. The effect of different parameter values on the generation of stable solitons is explored. In addition, we observe different resultant domains of the input beam evolving in the linear loss coefficient or cubic gain coefficient and Lévy index parameter planes. The results show that the evolution can lead to the formation of stable multipole solitons. It is also demonstrated that two solitons merge to form a single soliton. And, the relation between the merger distance and the initial amplitude is given.","PeriodicalId":16826,"journal":{"name":"Journal of Physics B: Atomic, Molecular and Optical Physics","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141680819","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":"Both the ionic and covalent bonds stabilize the W@Si12 cluster","authors":"Yue-Hong Yin, Xuehui Dai, Yan Zhang","doi":"10.1088/1361-6455/ad5e23","DOIUrl":"https://doi.org/10.1088/1361-6455/ad5e23","url":null,"abstract":"\u0000 Si is an important semiconductor material in the development of modern industry. With the miniaturization trend of semiconductor devices, the size of Si has reached the cluster size. The search for stable Si clusters is an important issue. In this work, the electronic structures and stability mechanism of the W@Si12 cluster are calculated by the first-principle calculations. Different from a C2v hexacapped trigonal prism structure of Si12, the W@Si12 cluster presents an embedded hexagonal prism structure with D6h symmetry. The addition of W atom leads to a higher stability. The molecular orbitals show superatomic characteristics for W@Si12 clusters, and their energy levels are more degenerate than that of the Si12 cluster. The population analysis indicates that a charge of 0.184 e is transferred from Si atoms to the center W atom, which suggests an ionic bonds for W-Si. The electron localization function further proves a covalent bond for Si-Si. The enhanced stability of the W@Si12 cluster is attributed to the combination of the ionic and covalent bonds.","PeriodicalId":16826,"journal":{"name":"Journal of Physics B: Atomic, Molecular and Optical Physics","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141685069","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":"A simple, practical experiment to investigate atomic wavefunction reduction within a Stern–Gerlach magnet","authors":"Michael Devereux","doi":"10.1088/1361-6455/ad5992","DOIUrl":"https://doi.org/10.1088/1361-6455/ad5992","url":null,"abstract":"For nearly one hundred years most quantum-mechanics texts have depicted a continuous, spin-direction superposition of the wavefunction of the silver atom traversing a Stern–Gerlach (S–G) magnet. But there are sound scientific arguments which deny that understanding. Schrodinger’s equation for that continuous wavefunction development cannot describe the transfer of energy from the magnetic field to that atom. Modern micro-fabrication techniques now make it possible to implement a simple, accessible experiment testing whether a spin superposition does continue in the magnet. Because the S–G experiment is the prototype for quantum measurement, that observation is crucial to implementing a realistic quantum theory of measurement.","PeriodicalId":16826,"journal":{"name":"Journal of Physics B: Atomic, Molecular and Optical Physics","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141505623","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}
D V Rezvan, A Pier, S Grundmann, N M Novikovskiy, N Anders, M Kircher, N Melzer, F Trinter, M S Schöffler, T Jahnke, R Dörner and Ph V Demekhin
{"title":"Nondipolar photoelectron angular distributions from fixed-in-space N2 molecules","authors":"D V Rezvan, A Pier, S Grundmann, N M Novikovskiy, N Anders, M Kircher, N Melzer, F Trinter, M S Schöffler, T Jahnke, R Dörner and Ph V Demekhin","doi":"10.1088/1361-6455/ad5893","DOIUrl":"https://doi.org/10.1088/1361-6455/ad5893","url":null,"abstract":"We investigate experimentally and theoretically the N 1s photoionization of fixed-in-space N2 molecules at a photon energy of 880 eV. In our experiment, we employed circularly polarized synchrotron radiation for the photoionization and coincident electron and fragment-ion detection using cold target recoil ion momentum spectroscopy. The accompanying angle-resolved calculations were carried out by the multichannel single-center method and code within the frozen-core Hartree–Fock approximation. The computed emission distributions exhibit two distinct features along the molecular axis, which are the results of a superposition of the direct and nearest-neighbor scattering amplitudes for the photoemission from two nitrogen atoms. In the electric-dipole approximation, these peaks are symmetric with respect to both nitrogen atoms. Including nondipole (retardation) effects in the calculations results in a simultaneous increase and decrease of the scattering peaks towards the nitrogen atoms pointing in the forward and backward directions along the light propagation, respectively. These theoretical findings are in agreement with our experimental findings.","PeriodicalId":16826,"journal":{"name":"Journal of Physics B: Atomic, Molecular and Optical Physics","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141512343","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}
Ling-Zheng Meng, Li-Chen Zhao, Thomas Busch and Yongping Zhang
{"title":"Controlling dark solitons on the healing length scale","authors":"Ling-Zheng Meng, Li-Chen Zhao, Thomas Busch and Yongping Zhang","doi":"10.1088/1361-6455/ad5895","DOIUrl":"https://doi.org/10.1088/1361-6455/ad5895","url":null,"abstract":"While usually the optical diffraction limit is setting a limit for the lengthscales on which a typical alkali Bose–Einstein condensate can be controlled, we show that in certain situations control via matter waves can achieve smaller resolutions. For this we consider a small number of impurity atoms which are trapped inside the density dip of a dark soliton state and show that any grey soliton state can be obtained by selectively driving the impurity atoms. This allows to fully control the position and velocity of the dark soliton, and also study controlled collisions between these non-linear objects.","PeriodicalId":16826,"journal":{"name":"Journal of Physics B: Atomic, Molecular and Optical Physics","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141512344","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}