arXiv - PHYS - Atomic Physics最新文献

{"title":"Emergent $s$-wave interactions in orbitally active quasi-two-dimensional Fermi gases","authors":"Colin J. Dale, Kevin G. S. Xie, Kiera Pond Grehan, Shizhong Zhang, Jeff Maki, Joseph H. Thywissen","doi":"arxiv-2408.00737","DOIUrl":"https://doi.org/arxiv-2408.00737","url":null,"abstract":"We investigate the scattering properties and bound states of a\u0000quasi-two-dimensional (q2D) spin-polarized Fermi gas near a $p$-wave Feshbach\u0000resonance. Strong confinement promotes the out-of-plane spatial wave functions\u0000to a discrete, gapped orbital degree of freedom. Exchange-antisymmetric orbital\u0000pair wave functions are predicted to give rise to low-energy q2D interactions\u0000with $s$-wave symmetry. Using radiofrequency (rf) spectroscopy, we observe the\u0000signature power-law scaling and the dimensional-crossover feature anticipated\u0000for the emergent $s$-wave channel. Additionally, we demonstrate that two types\u0000of low-energy dimers, with either $s$-wave and $p$-wave symmetry, could be\u0000formed via rf spin-flip association from an orbital mixture. These findings\u0000illustrate how gapped orbital degrees of freedom can provide additional control\u0000over scattering symmetries in strongly confined ultracold gases.","PeriodicalId":501039,"journal":{"name":"arXiv - PHYS - Atomic Physics","volume":"81 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141884239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Extracting doubly-excited state lifetimes in helium directly in the time domain with attosecond noncollinear four-wave-mixing spectroscopy","authors":"Patrick RupprechtDepartment of Chemistry, University of California, Berkeley, California, USAChemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA, Nicolette G. PuskarDepartment of Chemistry, University of California, Berkeley, California, USAChemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA, Daniel M. NeumarkDepartment of Chemistry, University of California, Berkeley, California, USAChemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA, Stephen R. LeoneDepartment of Chemistry, University of California, Berkeley, California, USAChemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, USADepartment of Physics, University of California, Berkeley, California, USA","doi":"arxiv-2408.00209","DOIUrl":"https://doi.org/arxiv-2408.00209","url":null,"abstract":"The helium atom, with one nucleus and two electrons, is a prototypical system\u0000to study quantum many-body dynamics. Doubly-excited states, or quantum states\u0000in which both electrons are excited by one photon, are showcase scenarios of\u0000electronic-correlation mediated effects. In this paper, the natural lifetimes\u0000of the doubly-excited $^1$P$^o$ 2s$n$p Rydberg series and the $^1$S$^e$ 2p$^2$\u0000dark state in helium in the 60 eV to 65 eV region are measured directly in the\u0000time domain with extreme-ultraviolet/near-infrared noncollinear attosecond\u0000four-wave-mixing (FWM) spectroscopy. The measured lifetimes are in agreement\u0000with lifetimes deduced from spectral linewidths and theoretical predictions,\u0000and the roles of specific decay mechanisms are considered. While complex\u0000spectral line shapes in the form of Fano resonances are common in absorption\u0000spectroscopy of autoionizing states, the background-free and thus homodyned\u0000character of noncollinear FWM results exclusively in Lorentzian spectral\u0000features in the absence of strong-field effects. The onset of strong-field\u0000effects that would affect the extraction of accurate natural lifetimes in\u0000helium by FWM is determined to be approximately 0.3 Rabi cycles. This study\u0000provides a systematic understanding of the FWM parameters necessary to enable\u0000accurate lifetime extractions, which can be utilized in more complex quantum\u0000systems such as molecules in the future.","PeriodicalId":501039,"journal":{"name":"arXiv - PHYS - Atomic Physics","volume":"217 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141884341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigating the hyperfine systematic error and relative phase in low spin-polarization alkali FID magnetometers","authors":"D. P. Hewatt, M. Ellmeier, C. Kiehl, T. S. Menon, J. W. Pollock, C. A. Regal, S. Knappe","doi":"arxiv-2408.00898","DOIUrl":"https://doi.org/arxiv-2408.00898","url":null,"abstract":"Alkali-metal optically-pumped magnetometers are prone to inaccuracies arising\u0000from the overlap of the average F = I + 1/2 and F = I - 1/2 ground-state Zeeman\u0000resonances. We employ density-matrix simulations and experiments to investigate\u0000how this hyperfine systematic error varies with spin polarization in a\u0000$^{87}$Rb free-induction-decay (FID) magnetometer. At low spin polarizations,\u0000($P leq 0.5$), this effect causes single-frequency magnetic-field extraction\u0000techniques to exhibit inaccuracies up to approximately 3.5 nT. Density-matrix\u0000simulations reveal that this bias can be traced to the relative amplitude and\u0000phase between the F = I $pm$ 1/2 hyperfine ground-state manifolds in the FID\u0000spin precession signal. We show that this systematic error can be mitigated\u0000using either a double-frequency fitting model that accounts for the relative\u0000amplitude and phase or synchronous-pulse pumping, that minimizes the F = 1\u0000contribution to the FID signal. Theoretical simulations predict accuracies\u0000within 0.5 nT for both techniques across a wide range of spin polarizations,\u0000suggesting a sevenfold enhancement over single-frequency extraction methods.\u0000Our experiments validate this, showcasing a variation in the extracted field\u0000below 1 nT, a 3.5-fold improvement compared to single-frequency extraction\u0000methods. Furthermore, the mitigation techniques demonstrate agreement of the\u0000extracted magnetic field within 1.5 nT.","PeriodicalId":501039,"journal":{"name":"arXiv - PHYS - Atomic Physics","volume":"68 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141939716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A neural network approach to running high-precision atomic computations","authors":"Pavlo Bilous, Charles Cheung, Marianna Safronova","doi":"arxiv-2408.00477","DOIUrl":"https://doi.org/arxiv-2408.00477","url":null,"abstract":"Modern applications of atomic physics, including the determination of\u0000frequency standards, and the analysis of astrophysical spectra, require\u0000prediction of atomic properties with exquisite accuracy. For complex atomic\u0000systems, high-precision calculations are a major challenge due to the\u0000exponential scaling of the involved electronic configuration sets. This\u0000exacerbates the problem of required computational resources for these\u0000computations, and makes indispensable the development of approaches to select\u0000the most important configurations out of otherwise intractably huge sets. We\u0000have developed a neural network (NN) tool for running high-precision atomic\u0000configuration interaction (CI) computations with iterative selection of the\u0000most important configurations. Integrated with the established pCI atomic\u0000codes, our approach results in computations with significantly reduced\u0000computational requirements in comparison with those without NN support. We\u0000showcase a number of NN-supported computations for the energy levels of\u0000Fe$^{16+}$ and Ni$^{12+}$, and demonstrate that our approach can be reliably\u0000used and automated for solving specific computational problems for a wide\u0000variety of systems.","PeriodicalId":501039,"journal":{"name":"arXiv - PHYS - Atomic Physics","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141884235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Final state interactions for high energy scattering off atomic electrons","authors":"Ryan Plestid, Mark B. Wise","doi":"arxiv-2407.21752","DOIUrl":"https://doi.org/arxiv-2407.21752","url":null,"abstract":"We consider the scattering of high energy leptons off bound atomic electrons\u0000focusing primarily on final state interactions i.e., the exchange of virtual\u0000photons between the outgoing energetic electron, and the heavy residual charged\u0000\"debris\" in the final state. These effects are inherently absent from\u0000calculations for a free electron at rest. Coulomb exchanges are enhanced by the\u0000large number of electrons in the atomic debris, and are unsuppressed by\u0000non-relativistic velocities in the debris. We find that these exchanges can be\u0000resummed using operator methods, and cancel at the level of the cross section\u0000until at least $O(alpha^3)$. Furthermore, we argue that both final {it and}\u0000initial state Coulomb exchanges (enhanced by the number of electrons in the\u0000atom) do not affect the cross section until at least $O(alpha^3)$. Transverse\u0000photon couplings to non relativistic electrons are proportional to their small\u0000velocities, and rotational invariance suppresses their contribution to\u0000$O(alpha^3)$. Our results are relevant for precision experiments involving\u0000neutrinos, electrons, positrons, and muons scattering off of atomic electrons\u0000in a fixed target.","PeriodicalId":501039,"journal":{"name":"arXiv - PHYS - Atomic Physics","volume":"40 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141863719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heavy particle quantum electrodynamics","authors":"Krzysztof Pachucki, Vladimir A. Yerokhin","doi":"arxiv-2407.20703","DOIUrl":"https://doi.org/arxiv-2407.20703","url":null,"abstract":"The quantum electrodynamic formalism is presented for the systematic and\u0000exact in $Z,alpha$ derivation of nuclear recoil corrections in hydrogenic\u0000systems.","PeriodicalId":501039,"journal":{"name":"arXiv - PHYS - Atomic Physics","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141863714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Complete three-dimensional vector polarimetry with a Rydberg atom rf electrometer","authors":"Peter K. Elgee, Kevin C. Cox, Joshua C. Hill, Paul D. Kunz, David H. Meyer","doi":"arxiv-2407.20369","DOIUrl":"https://doi.org/arxiv-2407.20369","url":null,"abstract":"Radio frequency (rf) receivers using Rydberg atoms offer appealing features\u0000over classical sensors, such as their size, frequency tuning range, and lack of\u0000field absorption. In this work, we extend the application space by\u0000demonstrating a Rydberg atom rf polarimeter. Using rf heterodyne with three\u0000independent and orthogonal local oscillators, we are able to extract the\u0000polarization ellipse of the field in three dimensions, in addition to the total\u0000amplitude of the field. We use the relative phases and amplitudes of the three\u0000generated heterodyne signals to measure the field amplitudes and phases along\u0000three cardinal axes giving the full three-dimensional polarization. We\u0000demonstrate this polarization measurement for incoming fields at different\u0000angles around the sensor. Lastly, we investigate the reception of data symbols\u0000encoded in the horizontal and vertical signal field polarizations and the phase\u0000between them. Our measurements yield an amplitude noise of 57\u0000$mu$V/m/$sqrt{text{Hz}}$ for horizontal polarization, 66\u0000$mu$V/m/$sqrt{text{Hz}}$ for vertical polarization, and a standard deviation\u0000of 0.094 rad in the phase between the field components.","PeriodicalId":501039,"journal":{"name":"arXiv - PHYS - Atomic Physics","volume":"124 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141863715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigations of electron removal processes in slow He$^{2+}$ and He$^{+}$-Ne$_2$ collisions indicate high Interatomic Coulombic Decay yield","authors":"Darij Starko, Tom Kirchner","doi":"arxiv-2407.20411","DOIUrl":"https://doi.org/arxiv-2407.20411","url":null,"abstract":"We implement an independent-atom and independent-electron model to\u0000investigate the collision systems of He$^{2+}$ and He$^{+}$ ion projectiles\u0000impinging on a neon dimer target. The dimer is set to be stationary at its\u0000equilibrium bond length with the projectile traveling parallel to the dimer\u0000axis at a speed corresponding to the collision energy of 10 keV/amu. Two\u0000approaches called multinomial and determinantal are used as an analysis of\u0000these collisions. Each of the analyses is broken down into two types of models\u0000that do not and do include a change in the projectile charge state due to\u0000electron capture from the dimer. All calculations are performed using both a\u0000frozen atomic target and a dynamic response model using the coupled-channel\u0000two-center basis generator method for orbital propagation. All one- and two-\u0000electron removal processes are calculated, though particular attention is paid\u0000to those that result in the Ne$^{+}$-Ne$^{+}$ fragmentation channel due to its\u0000association with interatomic Coulombic decay (ICD). We confirm in all analyses\u0000and models that Ne(2$s$) electron removal is strong so that ICD will contribute\u0000to dimer fragmentation as has been previously demonstrated. The model that\u0000takes into account the change in projectile charge state indicates that there\u0000is a pure ICD yield when utilizing a He$^{+}$ projectile.","PeriodicalId":501039,"journal":{"name":"arXiv - PHYS - Atomic Physics","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141863670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rydberg atom-based microwave electrometry using polarization spectroscopy","authors":"Naomy Duarte Gomes, Vinicius Marrara Pepino, Ben-Hur Viana Borges, Daniel Varela Magalhães, Reginaldo de Jesus Napolitano, Manuel Alejandro Lefrán Torres, Jorge Douglas Massayuki Kondo, Luis Gustavo Marcassa","doi":"arxiv-2407.20433","DOIUrl":"https://doi.org/arxiv-2407.20433","url":null,"abstract":"In this study, we investigated Rydberg atom-based microwave electrometry\u0000using polarization spectroscopy in a room-temperature vapor cell. By measuring\u0000Autler-Townes splitting in the electromagnetically induced transparency (EIT)\u0000spectrum, we determined that the minimum measurable microwave electric field is\u0000approximately five times lower than conventional EIT techniques. The results\u0000are well reproduced by a full optical Bloch equation model, which takes into\u0000account all the hyperfine levels involved. Subsequently, the EIT setup was used\u0000to characterize a custom microwave cylindrical lens, which increases the field\u0000at the focus by a factor of three, decreasing the minimum measurable microwave\u0000electric field by the same amount. Our results indicate that the combination of\u0000polarization spectroscopy and a microwave lens may enhance microwave\u0000electrometry.","PeriodicalId":501039,"journal":{"name":"arXiv - PHYS - Atomic Physics","volume":"169 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141863718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spin hierarchy in van der Waals molecule formation via ultracold three-body recombination","authors":"Jing-Lun Li, Paul S. Julienne, Johannes Hecker Denschlag, José P. D'Incao","doi":"arxiv-2407.18567","DOIUrl":"https://doi.org/arxiv-2407.18567","url":null,"abstract":"We theoretically investigate the product-state distribution of weakly bound\u0000diatomic van der Waals molecules via ultracold three-body recombination of\u0000bosonic alkali atoms. We find a two-level hierarchy of spin propensity rules at\u0000zero magnetic field. The primary propensity rule states that nearly all\u0000molecular products conserve the total hyperfine spin of reactant atomic pairs,\u0000while molecular products not conserving the total spin are highly suppressed.\u0000For the dominant molecular products, there is a secondary propensity to\u0000conserve certain spin components of the reactant pair such as the atomic\u0000hyperfine spins, or the total electronic or nuclear spins. The second\u0000propensity varies across species and depends fundamentally on the interplay\u0000between effective electronic exchange and hyperfine interactions. The spin\u0000sensitivity of product-state distribution can potentially open up new avenues\u0000for controlling state-to-state reaction rates in ultracold three-body\u0000recombination.","PeriodicalId":501039,"journal":{"name":"arXiv - PHYS - Atomic Physics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141863716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}