Pub Date : 2024-09-16DOI: 10.1103/physreva.110.033517
Y. C. Shi, C. J. Zhu, J. Y. Wu, J. Yang, Y. F. Zhang
We investigate the microwave-field-induced cross-phase modulation in a room-temperature coherently driven five-level inverted-Y-type system. By solving the optical Bloch equations via the Fourier transformation, we derive two nonlinearly coupled envelope equations governing the dynamics of left- and right-polarized components of a linearly polarized probe field. Under the weak probe field approximation, we show that the cross-phase modulation-induced phase difference between two components of the probe field is approximately proportional to the microwave field intensity. By choosing a specified probe field frequency, the group velocities for the left- and right-polarized components of the probe field match perfectly so that the phase difference can be detected at the end of the medium, enabling the undistorted detection of the microwave field. Considering the square-pulsed microwave field with a 50% duty cycle, we also demonstrate microwave communication by detecting the cross-phase modulation-induced phase difference.
我们研究了室温相干驱动五级倒 Y 型系统中微波场诱导的跨相位调制。通过傅立叶变换求解光学布洛赫方程，我们推导出两个非线性耦合包络方程，分别控制线性极化探针场的左极化和右极化分量的动态。在弱探针场近似条件下，我们证明探针场两个分量之间的交叉相位调制引起的相位差与微波场强度近似成正比。通过选择指定的探针场频率，探针场左偏振和右偏振分量的群速度完全匹配，这样就能在介质末端检测到相位差，从而实现对微波场的无扭曲检测。考虑到方波脉冲微波场的占空比为 50%，我们还通过检测交叉相位调制引起的相位差演示了微波通信。
{"title":"Microwave communication based on the cross-phase modulation in an inverted-Y-type Rydberg atomic system","authors":"Y. C. Shi, C. J. Zhu, J. Y. Wu, J. Yang, Y. F. Zhang","doi":"10.1103/physreva.110.033517","DOIUrl":"https://doi.org/10.1103/physreva.110.033517","url":null,"abstract":"We investigate the microwave-field-induced cross-phase modulation in a room-temperature coherently driven five-level inverted-Y-type system. By solving the optical Bloch equations via the Fourier transformation, we derive two nonlinearly coupled envelope equations governing the dynamics of left- and right-polarized components of a linearly polarized probe field. Under the weak probe field approximation, we show that the cross-phase modulation-induced phase difference between two components of the probe field is approximately proportional to the microwave field intensity. By choosing a specified probe field frequency, the group velocities for the left- and right-polarized components of the probe field match perfectly so that the phase difference can be detected at the end of the medium, enabling the undistorted detection of the microwave field. Considering the square-pulsed microwave field with a 50% duty cycle, we also demonstrate microwave communication by detecting the cross-phase modulation-induced phase difference.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"2 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142262615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Pub Date : 2024-09-16DOI: 10.1103/physreva.110.033516
G. Alagappan, C. E. Png
In this article, we demonstrate dense resonant peaks in the transmission spectra of a rectangular waveguide inscribed with a stretched moiré pattern. We investigated an array of silicon waveguides with sinusoidally modulated cladding of varying depth of modulation. The investigation reveals a critical depth of modulation that splits the geometries into weakly scattering and strongly scattering regimes. Geometries in the weakly scattering regime resemble Bragg waveguides with shallow cladding modulation, whereas in the strongly scattering regime, the geometries resemble chains of isolated dielectric particles. The guided mode photonic band gap for geometries in the strongly scattering regime is much larger than that of the weakly scattering regime. By inscribing stretched moiré patterns in the strongly scattering regime, we show that a large number of sharp peaks can be created in the transmission spectra of the waveguide. All periodic stretched moiré patterns can be identified with an R parameter. The R parameter indicates the ratio of the supercell period of the stretched system to the unstretched system. Our empirical study shows that the density of peaks linearly increases with R. The multiple resonance peaks evolve along well-defined trajectories with the quality factor defined by exponential functions of R.
在本文中，我们展示了刻有拉伸摩尔纹图案的矩形波导传输光谱中的密集谐振峰。我们研究了具有不同调制深度正弦调制包层的硅波导阵列。研究发现了一个临界调制深度，它将几何形状分为弱散射和强散射两种。弱散射状态下的几何形状类似于具有浅包层调制的布拉格波导，而在强散射状态下，几何形状类似于孤立的介质颗粒链。强散射机制下的几何形状的导模光子带隙远大于弱散射机制下的几何形状。通过在强散射机制中刻画拉伸莫尔纹图案，我们发现波导的透射光谱中可以产生大量尖锐的峰值。所有周期性拉伸莫尔纹都可以用一个 R 参数来识别。R 参数表示拉伸系统与非拉伸系统的超胞周期之比。我们的经验研究表明，峰值密度随 R 的增加而线性增加。多个共振峰沿着定义明确的轨迹演化，其品质因数由 R 的指数函数定义。
{"title":"Dense and sharp resonance peaks in stretched Moiré waveguides","authors":"G. Alagappan, C. E. Png","doi":"10.1103/physreva.110.033516","DOIUrl":"https://doi.org/10.1103/physreva.110.033516","url":null,"abstract":"In this article, we demonstrate dense resonant peaks in the transmission spectra of a rectangular waveguide inscribed with a stretched moiré pattern. We investigated an array of silicon waveguides with sinusoidally modulated cladding of varying depth of modulation. The investigation reveals a critical depth of modulation that splits the geometries into weakly scattering and strongly scattering regimes. Geometries in the weakly scattering regime resemble Bragg waveguides with shallow cladding modulation, whereas in the strongly scattering regime, the geometries resemble chains of isolated dielectric particles. The guided mode photonic band gap for geometries in the strongly scattering regime is much larger than that of the weakly scattering regime. By inscribing stretched moiré patterns in the strongly scattering regime, we show that a large number of sharp peaks can be created in the transmission spectra of the waveguide. All periodic stretched moiré patterns can be identified with an <i>R</i> parameter. The <i>R</i> parameter indicates the ratio of the supercell period of the stretched system to the unstretched system. Our empirical study shows that the density of peaks linearly increases with <i>R</i>. The multiple resonance peaks evolve along well-defined trajectories with the quality factor defined by exponential functions of <i>R</i>.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"95 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142262932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Pub Date : 2024-09-16DOI: 10.1103/physreva.110.033315
Nicolas Dupuis
We study the superfluid–Bose-glass transition in a one-dimensional lattice boson model with power-law decaying hopping amplitude , using bosonization and the nonperturbative functional renormalization group (FRG). When is smaller than a critical value , the U(1) symmetry is spontaneously broken, which leads to a density mode with nonlinear dispersion and dynamical exponent ; the superfluid phase is then stable for sufficiently weak disorder, contrary to the case of short-range hopping where disorder is a relevant perturbation when the Luttinger parameter is smaller than . In the presence of disorder, however, long-range hopping has no effect in the infrared limit and the FRG flow eventually becomes similar to that of a boson system with short-range hopping. This implies that the superfluid phase, when stable, exhibits a density mode with linear dispersion () and the superfluid–Bose-glass transition remains in the Berezinskii-Kosterlitz-Thouless universality class, while the Bose-glass fixed point is insensitive to long-range hopping. We compare our findings with a recent numerical study.
{"title":"Superfluid–Bose-glass transition in a system of disordered bosons with long-range hopping in one dimension","authors":"Nicolas Dupuis","doi":"10.1103/physreva.110.033315","DOIUrl":"https://doi.org/10.1103/physreva.110.033315","url":null,"abstract":"We study the superfluid–Bose-glass transition in a one-dimensional lattice boson model with power-law decaying hopping amplitude <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>t</mi><mrow><mi>i</mi><mo>−</mo><mi>j</mi></mrow></msub><mo>∼</mo><mn>1</mn><mo>/</mo><msup><mrow><mo>|</mo><mi>i</mi><mo>−</mo><mi>j</mi><mo>|</mo></mrow><mi>α</mi></msup></mrow></math>, using bosonization and the nonperturbative functional renormalization group (FRG). When <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>α</mi></math> is smaller than a critical value <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>α</mi><mi>c</mi></msub><mo><</mo><mn>3</mn></mrow></math>, the U(1) symmetry is spontaneously broken, which leads to a density mode with nonlinear dispersion and dynamical exponent <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>z</mi><mo>=</mo><mo>(</mo><mi>α</mi><mo>−</mo><mn>1</mn><mo>)</mo><mo>/</mo><mn>2</mn></mrow></math>; the superfluid phase is then stable for sufficiently weak disorder, contrary to the case of short-range hopping where disorder is a relevant perturbation when the Luttinger parameter is smaller than <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>3</mn><mo>/</mo><mn>2</mn></mrow></math>. In the presence of disorder, however, long-range hopping has no effect in the infrared limit and the FRG flow eventually becomes similar to that of a boson system with short-range hopping. This implies that the superfluid phase, when stable, exhibits a density mode with linear dispersion (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>z</mi><mo>=</mo><mn>1</mn></mrow></math>) and the superfluid–Bose-glass transition remains in the Berezinskii-Kosterlitz-Thouless universality class, while the Bose-glass fixed point is insensitive to long-range hopping. We compare our findings with a recent numerical study.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"95 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142262613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Pub Date : 2024-09-16DOI: 10.1103/physreva.110.033713
A. G. da Costa Moura, C. H. Monken
We present analytic expressions for the coincidence detection probability amplitudes of photon pairs generated by spontaneous parametric down-conversion in both momentum and position spaces, without using the Gaussian approximation and taking into account the effects of birefringence in the nonlinear crystal. We also present experimental data supporting our theoretical predictions, using Einstein-Podolsky-Rosen correlations as benchmarks, for eight different pump beam configurations.
{"title":"Einstein-Podolsky-Rosen correlations in spontaneous parametric down-conversion: Beyond the Gaussian approximation","authors":"A. G. da Costa Moura, C. H. Monken","doi":"10.1103/physreva.110.033713","DOIUrl":"https://doi.org/10.1103/physreva.110.033713","url":null,"abstract":"We present analytic expressions for the coincidence detection probability amplitudes of photon pairs generated by spontaneous parametric down-conversion in both momentum and position spaces, without using the Gaussian approximation and taking into account the effects of birefringence in the nonlinear crystal. We also present experimental data supporting our theoretical predictions, using Einstein-Podolsky-Rosen correlations as benchmarks, for eight different pump beam configurations.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"12 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142262617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Pub Date : 2024-09-16DOI: 10.1103/physreva.110.033316
Shao-Jun Li, Xiang Gao, Xue-Ting Fang, Lushuai Cao, Peter Schmelcher, Zhong-Kun Hu
Quantum simulation of a monopole-spin hybrid system is performed on the basis of a dipolar ultracold gas in a ladder lattice. The site-occupation states of the dipolar ladder lattice gas can spontaneously emulate both the monopole and spin excitations. The hopping of the atoms induces a particle conversion process between spin and monopole pairs, and the dipole-dipole interaction determines the spin-spin, spin-monopole, and monopole-monopole interactions. The anisotropic nature of the dipole-dipole interaction allows hereby for a flexible engineering of the designed hybrid system, and for a significant tunability of the interaction strengths. As a result, we encounter a rich phase diagram, and specifically a self-assembled Coulomb phase arises, in which monopoles and spins coexist and are orderly arranged according to the local Gauss's law. The Coulomb phase hosts a zoo of different types of quasiparticles and provides the possibility to simulate various phenomena in particle physics, such as a degenerate vacuum, particle decay, and conversion processes. Our work provides a significant extension of the scope of quantum simulations based on the anisotropy of dipolar interactions.
{"title":"Anisotropy-induced Coulomb phase and quasiparticle zoo in the atomic monopole-spin hybrid system","authors":"Shao-Jun Li, Xiang Gao, Xue-Ting Fang, Lushuai Cao, Peter Schmelcher, Zhong-Kun Hu","doi":"10.1103/physreva.110.033316","DOIUrl":"https://doi.org/10.1103/physreva.110.033316","url":null,"abstract":"Quantum simulation of a monopole-spin hybrid system is performed on the basis of a dipolar ultracold gas in a ladder lattice. The site-occupation states of the dipolar ladder lattice gas can spontaneously emulate both the monopole and spin excitations. The hopping of the atoms induces a particle conversion process between spin and monopole pairs, and the dipole-dipole interaction determines the spin-spin, spin-monopole, and monopole-monopole interactions. The anisotropic nature of the dipole-dipole interaction allows hereby for a flexible engineering of the designed hybrid system, and for a significant tunability of the interaction strengths. As a result, we encounter a rich phase diagram, and specifically a self-assembled Coulomb phase arises, in which monopoles and spins coexist and are orderly arranged according to the local Gauss's law. The Coulomb phase hosts a zoo of different types of quasiparticles and provides the possibility to simulate various phenomena in particle physics, such as a degenerate vacuum, particle decay, and conversion processes. Our work provides a significant extension of the scope of quantum simulations based on the anisotropy of dipolar interactions.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"16 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142262616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Pub Date : 2024-09-16DOI: 10.1103/physreva.110.032213
Manash Jyoti Sarmah, Himangshu Prabal Goswami
We theoretically identify the noise-induced coherent contribution to the ergotropy of a four-level quantum heat engine coupled to a unimodal quantum cavity. We utilize a protocol where the passive state's quasiprobabilities can be analytically identified from the population-coherence coupled reduced density matrix. The reduced density matrix elements are evaluated using a microscopic quantum master equation formalism. Multiple ergotropies within the same coherence interval, each characterized by a positive and pronounced coherent contribution, are observed. These ergotropies are a result of population inversion as well as quasiprobability-population inversion, controllable through the coherence measure parameters. The optimal flux and power of the engine are found to be at moderate values of ergotropy with increasing values of noise-induced coherence. The optimal power at different coherences is found to possess a constant ergotropy.
{"title":"Noise-induced coherent ergotropy of a quantum heat engine","authors":"Manash Jyoti Sarmah, Himangshu Prabal Goswami","doi":"10.1103/physreva.110.032213","DOIUrl":"https://doi.org/10.1103/physreva.110.032213","url":null,"abstract":"We theoretically identify the noise-induced coherent contribution to the ergotropy of a four-level quantum heat engine coupled to a unimodal quantum cavity. We utilize a protocol where the passive state's quasiprobabilities can be analytically identified from the population-coherence coupled reduced density matrix. The reduced density matrix elements are evaluated using a microscopic quantum master equation formalism. Multiple ergotropies within the same coherence interval, each characterized by a positive and pronounced coherent contribution, are observed. These ergotropies are a result of population inversion as well as quasiprobability-population inversion, controllable through the coherence measure parameters. The optimal flux and power of the engine are found to be at moderate values of ergotropy with increasing values of noise-induced coherence. The optimal power at different coherences is found to possess a constant ergotropy.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"30 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142262933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Pub Date : 2024-09-16DOI: 10.1103/physreva.110.033318
Fan Yang, Ruijie Du, Ran Qi, Peng Zhang
We investigate the scattering and two-body bound states of two ultracold atoms in a quasi-two-dimensional (quasi-2D) confinement, with the confinement potential being an infinitely deep square well (box potential) in the transverse () direction, and the motion of the atoms in the plane being free. Specifically, we calculate the effective 2D scattering length and 2D effective range parameter of the low-energy scattering, as well as the energy and the transverse-excited-mode probability of the bound states. Comparing these results with those obtained under a harmonic transverse confinement potential, which has the same characteristic length as the box potential, we find that in most of the cases the 2D effective range parameter for the box confinement is approximately 0.28 of the one for the harmonic confinement. Moreover, the transverse-excited-mode probability of the bound states for the box confinement is also much lower than the one for the harmonic confinement. These results suggest that the transverse excitation in the box confinement is notably weaker than the one in the harmonic confinement with the same characteristic length. Therefore, achieving quasi-2D ultracold gases well described by pure-2D effective models, particularly those with 2D contact interaction, is more feasible through box confinement. Our results are helpful for the quantum simulation of 2D many-body physics with ultracold atoms, e.g., the suppression of 2D effective range parameter may lead to an enhancement of quantum anomaly in two-dimensional Fermi gases. Additionally, our calculation method is applicable to the two-body problems of ultracold atoms in other types of quasi-2D confinements.
{"title":"Two ultracold atoms in a quasi-two-dimensional box confinement","authors":"Fan Yang, Ruijie Du, Ran Qi, Peng Zhang","doi":"10.1103/physreva.110.033318","DOIUrl":"https://doi.org/10.1103/physreva.110.033318","url":null,"abstract":"We investigate the scattering and two-body bound states of two ultracold atoms in a quasi-two-dimensional (quasi-2D) confinement, with the confinement potential being an infinitely deep square well (box potential) in the transverse (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>z</mi></math>) direction, and the motion of the atoms in the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>x</mi><mtext>−</mtext><mi>y</mi></mrow></math> plane being free. Specifically, we calculate the effective 2D scattering length and 2D effective range parameter of the low-energy scattering, as well as the energy and the transverse-excited-mode probability of the bound states. Comparing these results with those obtained under a harmonic transverse confinement potential, which has the same characteristic length as the box potential, we find that in most of the cases the 2D effective range parameter for the box confinement is approximately 0.28 of the one for the harmonic confinement. Moreover, the transverse-excited-mode probability of the bound states for the box confinement is also much lower than the one for the harmonic confinement. These results suggest that the transverse excitation in the box confinement is notably weaker than the one in the harmonic confinement with the same characteristic length. Therefore, achieving quasi-2D ultracold gases well described by pure-2D effective models, particularly those with 2D contact interaction, is more feasible through box confinement. Our results are helpful for the quantum simulation of 2D many-body physics with ultracold atoms, e.g., the suppression of 2D effective range parameter may lead to an enhancement of quantum anomaly in two-dimensional Fermi gases. Additionally, our calculation method is applicable to the two-body problems of ultracold atoms in other types of quasi-2D confinements.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"48 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142262930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
The interaction between solid materials and an optical vortex has garnered significant attention in recent years. Here, we study theoretically the high-order harmonic generation (HHG) of crystalline solids under the spatiotemporal optical-vortex light. We develop a quantum-orbit model to describe the intricate electron motion driven by a strong optical vortex, demonstrating the conservation law of spin and transverse orbital angular momenta in the HHG process. Harnessing the bicircular spatiotemporal vortex light field, we generate high-order harmonics with the hybrid spin and transverse orbital angular momentum. The proportions of different orbital angular-momentum components of harmonics in solids can also be tuned by adjusting the intensity ratio of the two light beams.
{"title":"Generation of high-order harmonics with hybrid spin and transverse orbital angular momentum from a crystalline solid","authors":"Jianing Zhang, Zijian Lyu, Lei Geng, Xiulan Liu, Yunquan Liu, Liang-You Peng","doi":"10.1103/physreva.110.033110","DOIUrl":"https://doi.org/10.1103/physreva.110.033110","url":null,"abstract":"The interaction between solid materials and an optical vortex has garnered significant attention in recent years. Here, we study theoretically the high-order harmonic generation (HHG) of crystalline solids under the spatiotemporal optical-vortex light. We develop a quantum-orbit model to describe the intricate electron motion driven by a strong optical vortex, demonstrating the conservation law of spin and transverse orbital angular momenta in the HHG process. Harnessing the bicircular spatiotemporal vortex light field, we generate high-order harmonics with the hybrid spin and transverse orbital angular momentum. The proportions of different orbital angular-momentum components of harmonics in solids can also be tuned by adjusting the intensity ratio of the two light beams.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"27 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142262938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Pub Date : 2024-09-16DOI: 10.1103/physreva.110.032811
Daniel Julian, Rian Koots, Jesús Pérez-Ríos
This work shows that feed-forward neural networks can predict the final rovibrational state distributions of inelastic and reactive processes of the reaction of in the hyperthermal regime, relevant for buffer gas chemistry. Furthermore, these models can be extended to the isotopologues of the reaction involving deuterium and tritium. In addition, we develop a neural network model that can learn across the chemical space based on the isotopologues of hydrogen. The model can predict the outcome of a reaction whose reactants have never been seen. This is done by training on the and reactions and subsequently predicting the reaction.
{"title":"Machine-learning models for atom-diatom reactions across isotopologues","authors":"Daniel Julian, Rian Koots, Jesús Pérez-Ríos","doi":"10.1103/physreva.110.032811","DOIUrl":"https://doi.org/10.1103/physreva.110.032811","url":null,"abstract":"This work shows that feed-forward neural networks can predict the final rovibrational state distributions of inelastic and reactive processes of the reaction of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>Ca</mi><mo>+</mo><msub><mi mathvariant=\"normal\">H</mi><mn>2</mn></msub><mo>→</mo><mi>CaH</mi><mo>+</mo><mi mathvariant=\"normal\">H</mi></mrow></math> in the hyperthermal regime, relevant for buffer gas chemistry. Furthermore, these models can be extended to the isotopologues of the reaction involving deuterium and tritium. In addition, we develop a neural network model that can learn across the chemical space based on the isotopologues of hydrogen. The model can predict the outcome of a reaction whose reactants have never been seen. This is done by training on the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>Ca</mi><mo>+</mo><msub><mi mathvariant=\"normal\">H</mi><mn>2</mn></msub></mrow></math> and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>Ca</mi><mo>+</mo><msub><mi mathvariant=\"normal\">T</mi><mn>2</mn></msub></mrow></math> reactions and subsequently predicting the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>Ca</mi><mo>+</mo><msub><mi mathvariant=\"normal\">D</mi><mn>2</mn></msub></mrow></math> reaction.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"25 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142262936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Pub Date : 2024-09-13DOI: 10.1103/physreva.110.033107
Kirill V. Bazarov, Oleg I. Tolstikhin
The theory of molecular Siegert states in a static electric field in the zero-range potential model is developed. The model admits extended analytical and accurate numerical treatments, which enables one to study tunneling ionization of large polyatomic molecules with complex geometry in strong fields beyond the weak-field approximation. The theory is illustrated by calculations for three model molecules reproducing the geometry of the real water, benzene, and leucine molecules. The field and orientation dependence of two major ionization observables, the ionization rate and the transverse momentum distribution of liberated electrons, is analyzed. The calculations reveal a number of strong-field effects not accounted for by the weak-field asymptotic theory. In particular, it is shown that vortex electrons are efficiently generated in tunneling ionization of large molecules at sufficiently strong fields, which opens a perspective for enantiosensitive rescattering photoelectron spectroscopy. The mechanism of tunneling-induced electron diffraction and its manifestation in the transverse momentum distribution are discussed.
{"title":"Generation of vortex electrons in tunneling ionization of polyatomic molecules: Exact results in the zero-range potential model","authors":"Kirill V. Bazarov, Oleg I. Tolstikhin","doi":"10.1103/physreva.110.033107","DOIUrl":"https://doi.org/10.1103/physreva.110.033107","url":null,"abstract":"The theory of molecular Siegert states in a static electric field in the zero-range potential model is developed. The model admits extended analytical and accurate numerical treatments, which enables one to study tunneling ionization of large polyatomic molecules with complex geometry in strong fields beyond the weak-field approximation. The theory is illustrated by calculations for three model molecules reproducing the geometry of the real water, benzene, and leucine molecules. The field and orientation dependence of two major ionization observables, the ionization rate and the transverse momentum distribution of liberated electrons, is analyzed. The calculations reveal a number of strong-field effects not accounted for by the weak-field asymptotic theory. In particular, it is shown that vortex electrons are efficiently generated in tunneling ionization of large molecules at sufficiently strong fields, which opens a perspective for enantiosensitive rescattering photoelectron spectroscopy. The mechanism of tunneling-induced electron diffraction and its manifestation in the transverse momentum distribution are discussed.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"40 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142262620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
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