The European Physical Journal D最新文献

{"title":"Discovering hidden physical mechanisms in Bose–Einstein condensates via deep-learning","authors":"Xiao-Dong Bai,&nbsp;Hao Xu,&nbsp;Dongxiao Zhang","doi":"10.1140/epjd/s10053-024-00841-7","DOIUrl":"10.1140/epjd/s10053-024-00841-7","url":null,"abstract":"<p>Discovering hidden physical mechanisms of a system, such as underlying partial differential equations (PDEs), is an intriguing subject that has not yet been fully explored. In particular, how to go beyond the traditional method to obtain the PDEs of complex systems is currently under active debate. In this work, we propose a deep-learning approach to discover the underlying Gross-Pitaevskii equations (GPEs) of one-dimensional Bose–Einstein condensates (BECs). The results show that such method is markedly superior to the traditional method due to advantages of the deep neural network. The former possesses the ability to obtain a parsimonious model with high accuracy and insensitivity to data noise, and can successfully discover the underlying GPEs that BECs should obey directly from the data even in the absence of a knowledge structure. More importantly, we find that such method is able to work well even for data with <span>(15%)</span> noise. Although the cases studied are proof-of-concept, the method provides a promising technique for unveiling hidden novel physical mechanisms in quantum systems from observations.</p>","PeriodicalId":789,"journal":{"name":"The European Physical Journal D","volume":"78 9","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142196117","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":"Optical simulation of triple-junction tandem solar cell based on SnO2 core nanowire array embedded in CZTSe, Cs2SnI6 and CuAlxIn1−xTe2 layers in bottom, middle and top cells, respectively","authors":"Mohamed Iheb Hammami,&nbsp;Rim Haji,&nbsp;Oussama Taleb Jlidi,&nbsp;Adnen Melliti","doi":"10.1140/epjd/s10053-024-00906-7","DOIUrl":"10.1140/epjd/s10053-024-00906-7","url":null,"abstract":"<div><p>This study focuses on optical optimizing triple-junction tandem solar cell using a novel combination of absorber materials and SnO₂ vertically aligned nanowire array buffer layers to enhance power conversion efficiency. The absorbers in the bottom, middle and top cells are CZTSe, Cs₂SnI₆ and CuAl_<i>x</i>In_1−<i>x</i>Te₂, respectively. The bandgaps of CZTSe and Cs₂SnI₆ are 1.05 and 1.62 eV, respectively. On the other hand, that of CuAl_<i>x</i>In_1−<i>x</i>Te₂ depends on <i>x</i> and varies from 1.71 to 2.2 eV. The top cell is coated by an anti-reflective layer. Rigorous coupled wave analysis simulations were used to optimize geometrical parameters of the tandem cell. Results show that the efficiency of the optimized tandem cell reaches 42.15% for <i>x</i> = 0.3 in CuAl_<i>x</i>In_1−<i>x</i>Te₂. This work helps advance the design of high-performance solar cells for sustainable energy applications.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":789,"journal":{"name":"The European Physical Journal D","volume":"78 9","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142196115","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":"Ultra-wide measurement range D-shaped photonic crystal fiber sensor based on surface plasmon resonance","authors":"Shuhuan Zhang,&nbsp;Ying Yang,&nbsp;Jiyu Dong","doi":"10.1140/epjd/s10053-024-00902-x","DOIUrl":"10.1140/epjd/s10053-024-00902-x","url":null,"abstract":"<div><p>In this paper, a kind of D-type photonic crystal fiber (PCF) sensor with an ultra-wide detection range based on micro-opening gold film coating is proposed. This sensor allows for the sensing detection of the refractive index (RI) of the analyte ranging from 1.30 to 1.42. However, the sensor coated with a micro-opening gold film only achieves an average wavelength sensitivity of 1489 nm/RIU in the x-polarization direction. To improve the performance of the sensor, an attempt was made to replace the micro-opening gold film with MoO₂ nanofilm. After simulation calculation, it was found that the RI detection range of the sensor using MoO₂ nanofilm became 1.33–1.39. Excitingly, the average wavelength sensitivity in the x-polarized direction reaches 17, 178 nm/RIU, which is 11.5 times better than the original sensor. This implies that the sensor is more sensitive to changes in the RI and can provide more accurate sensing and detection results. It has been demonstrated that the performance of a D-type PCF sensor can be significantly improved by using MoO₂ nanofilm. This improvement helps to expand the application domain of sensors and enhance the accuracy of sensing detection. We believe that this research result has important implications for the development of fiber sensor technologies.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div><div><p>Ultra-wide refractive index detection range fiber optic sensor</p></div></div></figure></div></div>","PeriodicalId":789,"journal":{"name":"The European Physical Journal D","volume":"78 8","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142196124","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":"Theoretical analysis of H/D isotope effect on the binding of a positron to acetaldehyde molecule","authors":"Kaito Dohi,&nbsp;Masanori Tachikawa,&nbsp;Yukiumi Kita","doi":"10.1140/epjd/s10053-024-00871-1","DOIUrl":"10.1140/epjd/s10053-024-00871-1","url":null,"abstract":"<p>We theoretically analyzed positron affinities (PAs) of acetaldehyde (CH₃CHO) and its deuterated (CD₃CDO) molecules at vibrational excited states with multi-component molecular orbital and vibrational quantum Monte Carlo methods. In the fundamental tone states, the PA value at the C=O stretching vibrational mode of acetaldehyde becomes increased by 9.8 meV (+ 12%) from the vibrational ground state of 84.5 meV, while that at the C-H (aldehyde group) stretching vibrational mode decreased by 2.8 meV (<span>(-)</span>3%). We also confirmed that each vibrational state has a different H/D isotope shift in PA values. Such non-uniformity in quantum vibrational influence on PA values and its H/D isotope shifts dominantly arise from the change in dipole moment by vibrational excitations.</p>","PeriodicalId":789,"journal":{"name":"The European Physical Journal D","volume":"78 8","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142196118","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":"Tunable photonic differentiator via Bloch surface waves","authors":"Jian Shi,&nbsp;Jun Li,&nbsp;Cuicui Li,&nbsp;Yuqiu Zhang,&nbsp;Jiangnan Lv,&nbsp;Yan Zhan,&nbsp;Xianping Wang,&nbsp;Yibin Huang,&nbsp;Jian Wu","doi":"10.1140/epjd/s10053-024-00867-x","DOIUrl":"10.1140/epjd/s10053-024-00867-x","url":null,"abstract":"<div><p>Optical differentiation is an exceptional real-time edge detection technology that enables extracting the image features, yet current optical differentiators are still lacking a resolution tunability. Based on the Bloch surface waves excited in a prism/one-dimensional photonic crystal structure, a wavelength-tuned optical differentiator with a high sensitivity (<span>(partial {r}_{s}/partial lambda =3.5times {10}^{3})</span>) is proposed since any minute variation of the wavelength will easily give rise to a dramatic change in the Goos–Hänchen shifts of two reflected orthogonal components. Via the polarization transformation and extinction, the reflected output field can be approximately expressed as a first-order differential of the input field, and thus, it can operate the edge detection along one orientation. Our scheme can extend to two-dimensional edge detection by rotating the object and may find potential applications in cell and molecular imaging.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":789,"journal":{"name":"The European Physical Journal D","volume":"78 8","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142196119","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":"The influence of experimental conditions on absolute beam density measurements for NH(_3) and H","authors":"Rahul Pandey,&nbsp;Lok Yiu Wu,&nbsp;Lucy Morris,&nbsp;Paul Regan,&nbsp;Brianna R. Heazlewood","doi":"10.1140/epjd/s10053-024-00899-3","DOIUrl":"10.1140/epjd/s10053-024-00899-3","url":null,"abstract":"<p>In order to establish important reaction properties, such as rate coefficients, it is often necessary to know the number of reactants that are present in an interaction region. The absolute number densities of pulsed supersonic molecular (NH<span>(_3)</span>) and atomic (H) beams are reported using a laser-based detection method, under a range of experimental conditions including photolysis, Zeeman deceleration, and magnetic focusing. Time-averaged densities of (3.6 ± 2.7) <span>(times )</span> 10<span>(^4)</span> cm<span>(^{-3})</span> are reported for successfully Zeeman-decelerated and magnetically focused H atoms, generated by the photodissociation of precursor NH<span>(_3)</span> molecules. Without the magnetic guide components in the beamline, the density of the target radicals of interest is somewhat lower, at (2.5 ± 1.8) <span>(times )</span> 10<span>(^4)</span> cm<span>(^{-3})</span>. The average density of the undecelerated H atom beam is approximately an order of magnitude higher (2.9 ± 1.9) <span>(times )</span> 10<span>(^5)</span> cm<span>(^{-3})</span>, with the average density of the molecular ammonia beam over two orders of magnitude higher again (5.1 ± 2.9) <span>(times )</span> 10<span>(^7)</span> cm<span>(^{-3})</span>. The average number densities measured for the two different species of interest in this work span more than three orders of magnitude. These findings highlight the need for accurate and precise experimental measurements of number densities—for each species of interest, under the appropriate experimental conditions—before doing absolute rate coefficient calculations.</p>","PeriodicalId":789,"journal":{"name":"The European Physical Journal D","volume":"78 8","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjd/s10053-024-00899-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142196120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Probe absorption characteristics and Kerr effect of a hybrid phonon-spin-magnon system","authors":"Qing-hong Liao,&nbsp;Chen-ting Deng,&nbsp;Hai-yan Qiu","doi":"10.1140/epjd/s10053-024-00896-6","DOIUrl":"10.1140/epjd/s10053-024-00896-6","url":null,"abstract":"<div><p>We theoretically explore the absorption spectra and Kerr effect of a phonon-spin-magnon hybrid system, in which the nitrogen-vacancy (NV) center is coupled with a yttrium iron garnet (YIG) crystal and a mechanical resonator simultaneously. The results indicate that vacuum Rabi splitting can occur in the absorption spectrum by modulating the coupling strength between the YIG sphere and the NV center. We show the vacuum Rabi splitting and the transparency based on mechanically induced coherent population oscillation (MICPO) to be adjusted by the decay rate of the YIG sphere and the mechanical resonator, respectively. Moreover, it is indicated the absorption spectra can be flexibly tuned by changing the frequency tuning of the spin-pump field. Furthermore, the nonlinear Kerr effect is controllable via varying the Rabi frequency. The study could provide a way for general applications in quantum computing devices and quantum information processing.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":789,"journal":{"name":"The European Physical Journal D","volume":"78 8","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142196123","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":"R-matrix with time-dependence calculations for three-sideband RABBITT in helium","authors":"A. T. Bondy,&nbsp;J. C. del Valle,&nbsp;S. Saha,&nbsp;K. R. Hamilton,&nbsp;D. Bharti,&nbsp;A. Harth,&nbsp;K. Bartschat","doi":"10.1140/epjd/s10053-024-00900-z","DOIUrl":"10.1140/epjd/s10053-024-00900-z","url":null,"abstract":"<p>Following up on a recent paper (Bharti et al. in Phys Rev A 109:023110, 2024), we compare the predictions from several <i>R</i>-matrix with time-dependence calculations for a modified three-sideband version of the “reconstruction of attosecond beating by interference of two-photon transitions” (RABBITT) configuration applied to helium. Except for the special case of the threshold sideband, which appears to be very sensitive to the details of coupling to the bound Rydberg states, increasing the number of coupled states in the close-coupling expansion used to describe the ejected-electron–residual-ion interaction hardly changes the results. Consequently, the remaining discrepancies between the experimental data and the theoretical predictions are likely due to uncertainties in the experimental parameters, particularly the detailed knowledge of the laser pulse.</p>","PeriodicalId":789,"journal":{"name":"The European Physical Journal D","volume":"78 8","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142196121","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":"Radiative and opacity data obtained from large-scale atomic structure calculations and from statistical simulations for the spectral analysis of kilonovae in their photospheric and nebular phases: the sample case of Er III","authors":"Jérôme Deprince,&nbsp;Helena Carvajal Gallego,&nbsp;Sirine Ben Nasr,&nbsp;Lucas Maison,&nbsp;Jean-Christophe Pain,&nbsp;Patrick Palmeri,&nbsp;Pascal Quinet","doi":"10.1140/epjd/s10053-024-00897-5","DOIUrl":"10.1140/epjd/s10053-024-00897-5","url":null,"abstract":"<p>This study is an overview of the atomic data and opacity computations performed by the Atomic Physics and Astrophysics Unit of Mons University in the context of kilonova emission following neutron star mergers, in both the photospheric and nebular phases. In this work, as a sample case, we focus on a specific lanthanide ion, namely Er III. As far as the LTE photospheric phase of the kilonova ejecta is concerned, we present our calculations using both a theoretical method (the pseudo-relativistic Hartree-Fock method, <span>HFR</span>) and a statistical approach (the Resolved Transition Array approach, RTA) to obtain the atomic data required to estimate the Er III expansion opacity for typical conditions expected in kilonova ejecta one day after the merger. In order to draw the limitations of both of our strategies, the results obtained using the latter are compared, and a calibration procedure of the <span>HFR</span> atomic data in this context is also discussed. Concerning the kilonova ejecta nebular phase, atomic parameters that characterize forbidden lines in Er III are calculated using <span>HFR</span> as well as another computational approach, namely the Multiconfiguration Dirac–Hartree–Fock (<span>MCDHF</span>) method. The potential detection of such lines in late-phase kilonova spectra is then discussed.</p>","PeriodicalId":789,"journal":{"name":"The European Physical Journal D","volume":"78 8","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142196126","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":"High precision in a Fourier-transform spectrum of protactinium: extensive weighted least-squares fits of peak wavenumbers for analysis of fine and hyperfine structure","authors":"Sophie Kröger","doi":"10.1140/epjd/s10053-024-00895-7","DOIUrl":"10.1140/epjd/s10053-024-00895-7","url":null,"abstract":"&lt;p&gt;A Fourier-transform recording of protactinium in the infrared range is reanalysed with high precision in order to determine the hyperfine interaction constants &lt;i&gt;A&lt;/i&gt; and &lt;i&gt;B&lt;/i&gt;. Starting with a selection of best lines and least-squares fits of hyperfine structure intervals, large systems of linear equations compare experimental hyperfine peak wavenumbers with a theoretical representation. The theoretical representation is based on Ritz’s combination principle and Casimir’s formula according to the existing classification. Weighted least-squares fits allow a discrimination between unperturbed and perturbed data such as blended hyperfine structure components. For the first time, the wavenumbers of the hyperfine components of more than 600 lines are fitted using the characteristics of about 250 levels as parameters. When adding adjustable wavenumber-scale correction parameters, global consistency for the whole IR spectrum is obtained with local limits of about &lt;span&gt;(0.3,times 10^{-3})&lt;/span&gt; cm&lt;span&gt;(^{-1})&lt;/span&gt;. This demonstrates the high precision in both recording and analysis. The values of the fine structure energies are revised. Standard errors around 0.1 &lt;span&gt;(times 10^{-3})&lt;/span&gt; cm&lt;span&gt;(^{-1})&lt;/span&gt; for the &lt;i&gt;A&lt;/i&gt; constants and 10&lt;span&gt;(^{-3})&lt;/span&gt; cm&lt;span&gt;(^{-1})&lt;/span&gt; for the &lt;i&gt;B&lt;/i&gt; constants and the fine structure energies are achieved. Representative examples illustrate extensive results obtained for atomic protactinium. This high precision facilitates further search for new energy levels, and 20 new levels were presented. &lt;b&gt;Foreword&lt;/b&gt; The data presented here are the results of a study carried out at the Laboratoire Aimé Cotton (LAC) at Paris-Orsay in the years 2003 and 2004, when I was there for a research stay. At this time, I worked together with Jean-François Wyart and Annie Ginibre on the re-examination of protactinium spectra that have been measured about 30 years earlier and that were available in the form of a printed list of peak wavenumbers and a printed paper chart of the intensity profile. The spectra had already been analysed, but there was still a lot of additional information that could be extracted from the spectra with time and effort. The review of the data, the selection of the data and the step-by-step optimization of the data set took a lot of time. When I returned to Berlin in 2004, we had made good progress, but in principle, it is like a bottomless pit. We continued together to optimize the data and tried to the finishing touches to it. At some point, we decided that we had reached a ‘level of maturity’ where the data could be published. We have discussed a lot about how detailed the text should be. This discussion has dragged on over the years and this project has repeatedly been lost in the stream of other everyday tasks. Every now and then there was a small attempt to return to this topic, but it quickly got lost in the daily hustle and bustle. In 2012, we presented the results at a co","PeriodicalId":789,"journal":{"name":"The European Physical Journal D","volume":"78 8","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjd/s10053-024-00895-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142196125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}