Pub Date : 2024-09-11DOI: 10.1088/1367-2630/ad7632
Zhen-Lin Jia, Shu-Chen Wang, Tong Li, Xiao-Wei Jin and De-Sheng Xue
Dynamics of magnetization M driven by microwave are derived analytically from the nonlinear Landau–Lifshitz–Gilbert equation. Analytical M and susceptibility are obtained self-consistently under a positive circularly polarized microwave field, , with frequency , which is perpendicular to a static field, . It is found that the orbital of M is always a cone along H. However, with increasing h the polar angle of M initially increases, then keeps 90° when in ferromagnetic resonance (FMR) mode, where is Gilbert damping constant and is gyromagnetic ratio. These effects result in a nonlinear variation of FMR signal as h increases to , where the maximum of resonance peak decreases from a steady value, linewidth increases from a decreasing trend. These analytical solutions provide a complete picture of the dynamics of M with different h and H.
从非线性 Landau-Lifshitz-Gilbert 方程分析得出微波驱动的磁化 M 的动力学。在正圆极化微波场（频率为 ，垂直于静态场（H））下，自洽地得到了分析磁化率和磁感应强度。 然而，随着 h 的增大，磁化率的极角开始增大，然后在铁磁共振（FMR）模式下保持 90°，其中吉尔伯特阻尼常数为 ，回旋磁比为 。这些效应导致 FMR 信号随着 h 的增大呈非线性变化，共振峰的最大值从稳定值减小，线宽从减小趋势增大。这些分析解提供了不同 h 和 H 时 M 的动态全貌。
{"title":"Large-angle analytical solution of magnetization precession in ferromagnetic resonance","authors":"Zhen-Lin Jia, Shu-Chen Wang, Tong Li, Xiao-Wei Jin and De-Sheng Xue","doi":"10.1088/1367-2630/ad7632","DOIUrl":"https://doi.org/10.1088/1367-2630/ad7632","url":null,"abstract":"Dynamics of magnetization M driven by microwave are derived analytically from the nonlinear Landau–Lifshitz–Gilbert equation. Analytical M and susceptibility are obtained self-consistently under a positive circularly polarized microwave field, , with frequency , which is perpendicular to a static field, . It is found that the orbital of M is always a cone along H. However, with increasing h the polar angle of M initially increases, then keeps 90° when in ferromagnetic resonance (FMR) mode, where is Gilbert damping constant and is gyromagnetic ratio. These effects result in a nonlinear variation of FMR signal as h increases to , where the maximum of resonance peak decreases from a steady value, linewidth increases from a decreasing trend. These analytical solutions provide a complete picture of the dynamics of M with different h and H.","PeriodicalId":19181,"journal":{"name":"New Journal of Physics","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214693","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 : 2024-09-11DOI: 10.1088/1367-2630/ad7492
Thomas Pfeifer, Matthias Wollenhaupt and Manfred Lein
We train a model atom to recognize pixel-drawn digits based on hand-written numbers in the range 0–9, employing intense light–matter interaction as a computational resource. For training, the images of the digits are converted into shaped laser pulses (data input pulses). Simultaneously with an input pulse, another shaped pulse (program pulse), polarized in the orthogonal direction, is applied to the atom and the system evolves quantum mechanically according to the time-dependent Schrödinger equation. The purpose of the optimal program pulse is to direct the system into specific atomic final states (classification states) that correspond to the input digits. A success rate of about 40% is achieved when using a basic optimization scheme that might be limited by the computational resources for finding the optimal program pulse in a high-dimensional search space. Our key result is the demonstration that the laser-programmed atom is able to generalize, i.e. successful classification is not limited to the training examples, but also the classification of previously unseen images is improved by training. This atom-sized machine-learning image-recognition scheme operates on time scales down to tens of femtoseconds, is scalable towards larger (e.g. molecular) systems, and is readily reprogrammable towards other learning/classification tasks. An experimental implementation of the scheme using ultrafast polarization pulse shaping and differential photoelectron detection is within reach.
{"title":"Ultrafast artificial intelligence: machine learning with atomic-scale quantum systems","authors":"Thomas Pfeifer, Matthias Wollenhaupt and Manfred Lein","doi":"10.1088/1367-2630/ad7492","DOIUrl":"https://doi.org/10.1088/1367-2630/ad7492","url":null,"abstract":"We train a model atom to recognize pixel-drawn digits based on hand-written numbers in the range 0–9, employing intense light–matter interaction as a computational resource. For training, the images of the digits are converted into shaped laser pulses (data input pulses). Simultaneously with an input pulse, another shaped pulse (program pulse), polarized in the orthogonal direction, is applied to the atom and the system evolves quantum mechanically according to the time-dependent Schrödinger equation. The purpose of the optimal program pulse is to direct the system into specific atomic final states (classification states) that correspond to the input digits. A success rate of about 40% is achieved when using a basic optimization scheme that might be limited by the computational resources for finding the optimal program pulse in a high-dimensional search space. Our key result is the demonstration that the laser-programmed atom is able to generalize, i.e. successful classification is not limited to the training examples, but also the classification of previously unseen images is improved by training. This atom-sized machine-learning image-recognition scheme operates on time scales down to tens of femtoseconds, is scalable towards larger (e.g. molecular) systems, and is readily reprogrammable towards other learning/classification tasks. An experimental implementation of the scheme using ultrafast polarization pulse shaping and differential photoelectron detection is within reach.","PeriodicalId":19181,"journal":{"name":"New Journal of Physics","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214687","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 : 2024-09-11DOI: 10.1088/1367-2630/ad762f
Ya Zhang, Feng Zhai and Wei Jiang
Owing to the inherent characteristics of collective excitations in graphene, electrical control of edge plasmons is highly desirable for nanoplasmonic applications. This study investigates valley-polarized edge pseudomagnetoplasmons in a graphene p–n junction subjected to a strain-induced pseudomagnetic field. A four-component hydrodynamic model is employed and solved via the Wiener–Hopf method, revealing the coexistence of three plasmon modes, including counterpropagating acoustic edge modes, gapless topological edge states, and zero modes. The valley polarization, as determined from the numerically exact solution, is stronger than that predicted by the approximate models. Notably, the confinement of edge plasmons at the graphene p–n junction significantly exceeds that at the graphene/vacuum interface, possibly because of the electron–hole attraction. Furthermore, gate-controlled subwavelength confinement is successfully achieved by applying an appropriate gate voltage, thereby highlighting a unique and promising attribute of edge pseudomagnetoplasmons in graphene p–n junctions.
{"title":"Valley-polarized edge plasmons in graphene p–n junctions with pseudomagnetic fields","authors":"Ya Zhang, Feng Zhai and Wei Jiang","doi":"10.1088/1367-2630/ad762f","DOIUrl":"https://doi.org/10.1088/1367-2630/ad762f","url":null,"abstract":"Owing to the inherent characteristics of collective excitations in graphene, electrical control of edge plasmons is highly desirable for nanoplasmonic applications. This study investigates valley-polarized edge pseudomagnetoplasmons in a graphene p–n junction subjected to a strain-induced pseudomagnetic field. A four-component hydrodynamic model is employed and solved via the Wiener–Hopf method, revealing the coexistence of three plasmon modes, including counterpropagating acoustic edge modes, gapless topological edge states, and zero modes. The valley polarization, as determined from the numerically exact solution, is stronger than that predicted by the approximate models. Notably, the confinement of edge plasmons at the graphene p–n junction significantly exceeds that at the graphene/vacuum interface, possibly because of the electron–hole attraction. Furthermore, gate-controlled subwavelength confinement is successfully achieved by applying an appropriate gate voltage, thereby highlighting a unique and promising attribute of edge pseudomagnetoplasmons in graphene p–n junctions.","PeriodicalId":19181,"journal":{"name":"New Journal of Physics","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214691","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 : 2024-09-10DOI: 10.1088/1367-2630/ad7630
B K Nally and P M R Brydon
Motivated by the recent discovery of a possible field-mediated parity switch within the superconducting state of CeRh2As2 (Khim et al 2021 Science373 1012), we thoroughly investigate the dependence of the superconducting state of a strongly-coupled Rashba mono- and bilayer on internal parameters and an applied magnetic field. The role of interlayer pairing, spin orbit coupling, doping rate and applied magnetic field and their interplay was examined numerically at low temperature within a t-J-like model, uncovering complex phase diagrams and transitions between superconducting states with different symmetry.
受最近发现 CeRh2As2 超导态中可能存在场介导的奇偶性开关（Khim et al 2021 Science373 1012）的启发，我们深入研究了强耦合拉什巴单层和双层超导态对内部参数和外加磁场的依赖性。我们在一个类似 t-J 的模型中，对低温下层间配对、自旋轨道耦合、掺杂率和外加磁场的作用及其相互影响进行了数值研究，揭示了复杂的相图和不同对称性超导态之间的转变。
{"title":"Phase diagram of strongly-coupled Rashba systems","authors":"B K Nally and P M R Brydon","doi":"10.1088/1367-2630/ad7630","DOIUrl":"https://doi.org/10.1088/1367-2630/ad7630","url":null,"abstract":"Motivated by the recent discovery of a possible field-mediated parity switch within the superconducting state of CeRh2As2 (Khim et al 2021 Science373 1012), we thoroughly investigate the dependence of the superconducting state of a strongly-coupled Rashba mono- and bilayer on internal parameters and an applied magnetic field. The role of interlayer pairing, spin orbit coupling, doping rate and applied magnetic field and their interplay was examined numerically at low temperature within a t-J-like model, uncovering complex phase diagrams and transitions between superconducting states with different symmetry.","PeriodicalId":19181,"journal":{"name":"New Journal of Physics","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214694","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 : 2024-09-10DOI: 10.1088/1367-2630/ad7636
Jiabin Wang, Xilai Bao, Jinxia Chen, Mengting Zou, Yali Xie, Run-Wei Li, Xiaoguang Li, Yanwei Cao and Baomin Wang
Perpendicular exchange bias (PEB) is highly desirable for the development of advanced nanoscale spintronics devices. The attainment of conventional PEB typically involves a field-cooling process through the Néel temperature of antiferromagnetic materials. In this study, we demonstrated the realization of spontaneous PEB (SPEB) in IrMn/[Co/Pt]3 multilayers utilizing isothermal crystallization of IrMn at room temperature (RT). And the SPEB generated isothermally at IrMn/Co interface does not destroy the perpendicular magnetic anisotropy of the multilayers. The magnetic domains of the multilayers captured by Kerr microscopy after different magnetization time also indicate the generation of SPEB. The magnitude of SPEB can be controllable by varying the isothermal magnetization time and the annealing temperature of IrMn. The relationship between magnetization waiting time and SPEB reveals that even slight isothermal crystallization can generate substantial SPEB. Our results provide an alternative approach to isothermally generate PEB in IrMn/[Co/Pt]3 multilayers at RT.
{"title":"Room-temperature spontaneous perpendicular exchange bias in IrMn/[Co/Pt]3 multilayers","authors":"Jiabin Wang, Xilai Bao, Jinxia Chen, Mengting Zou, Yali Xie, Run-Wei Li, Xiaoguang Li, Yanwei Cao and Baomin Wang","doi":"10.1088/1367-2630/ad7636","DOIUrl":"https://doi.org/10.1088/1367-2630/ad7636","url":null,"abstract":"Perpendicular exchange bias (PEB) is highly desirable for the development of advanced nanoscale spintronics devices. The attainment of conventional PEB typically involves a field-cooling process through the Néel temperature of antiferromagnetic materials. In this study, we demonstrated the realization of spontaneous PEB (SPEB) in IrMn/[Co/Pt]3 multilayers utilizing isothermal crystallization of IrMn at room temperature (RT). And the SPEB generated isothermally at IrMn/Co interface does not destroy the perpendicular magnetic anisotropy of the multilayers. The magnetic domains of the multilayers captured by Kerr microscopy after different magnetization time also indicate the generation of SPEB. The magnitude of SPEB can be controllable by varying the isothermal magnetization time and the annealing temperature of IrMn. The relationship between magnetization waiting time and SPEB reveals that even slight isothermal crystallization can generate substantial SPEB. Our results provide an alternative approach to isothermally generate PEB in IrMn/[Co/Pt]3 multilayers at RT.","PeriodicalId":19181,"journal":{"name":"New Journal of Physics","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214696","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 : 2024-09-10DOI: 10.1088/1367-2630/ad7633
Jia-Bao Ji, Anatoli S Kheifets, Meng Han, Kiyoshi Ueda and Hans Jakob Wörner
Determination and interpretation of Wigner-like photoionisation delays is one of the most active fields of attosecond science. Previous results have suggested that large photoionisation delays are associated with structured continua, but a quantitative relation between photoionisation cross sections and time delays has been missing. Here, we derive a Kramers–Kronig-like relation between these quantities and demonstrate its validity for (anti)resonances. This new concept defines a topological analysis, which rationalises the sign of photoionisation delays and thereby sheds new light on a long-standing controversy regarding the sign of the photoionisation delay near the Ar 3s Cooper minimum. Our work bridges traditional photoionisation spectroscopy with attosecond chronoscopy and offers new methods for analysing and interpreting photoionisation delays.
维格纳类光电离延迟的测定和解释是阿秒科学最活跃的领域之一。之前的研究结果表明，大的光电离延迟与结构连续体有关，但光电离截面与时间延迟之间的定量关系一直缺失。在这里，我们推导出了这些量之间类似于克拉默-克罗尼格的关系，并证明了其（反）共振的有效性。这一新概念定义了一种拓扑分析，它合理地解释了光电离延迟的符号，从而为有关 Ar 3s 库珀最小值附近光电离延迟符号的长期争议带来了新的启示。我们的研究工作将传统的光电离光谱学与阿秒计时学结合起来，为分析和解释光电离延迟提供了新方法。
{"title":"Relation between photoionisation cross sections and attosecond time delays","authors":"Jia-Bao Ji, Anatoli S Kheifets, Meng Han, Kiyoshi Ueda and Hans Jakob Wörner","doi":"10.1088/1367-2630/ad7633","DOIUrl":"https://doi.org/10.1088/1367-2630/ad7633","url":null,"abstract":"Determination and interpretation of Wigner-like photoionisation delays is one of the most active fields of attosecond science. Previous results have suggested that large photoionisation delays are associated with structured continua, but a quantitative relation between photoionisation cross sections and time delays has been missing. Here, we derive a Kramers–Kronig-like relation between these quantities and demonstrate its validity for (anti)resonances. This new concept defines a topological analysis, which rationalises the sign of photoionisation delays and thereby sheds new light on a long-standing controversy regarding the sign of the photoionisation delay near the Ar 3s Cooper minimum. Our work bridges traditional photoionisation spectroscopy with attosecond chronoscopy and offers new methods for analysing and interpreting photoionisation delays.","PeriodicalId":19181,"journal":{"name":"New Journal of Physics","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214695","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}
Mode pairing quantum key distribution (MP-QKD) overcomes the repeaterless bound without requiring phase locking and phase tracking. However, MP-QKD still assumes that the light source is trusted, which can present challenges in practical deployments and potentially introduce security vulnerabilities. In this paper, we propose a light source monitoring (LSM) scheme that guarantees the security of MP-QKD with the untrusted light sources. The simulation results demonstrate that, when considering untrusted light sources, the performance of MP-QKD with the LSM scheme remains nearly identical to that of ideal MP-QKD, even in the presence of the source fluctuations. Furthermore, we simplify some of the complex integration calculations involved in simulating the observed quantities of MP-QKD, which reduces the running time of the parameter optimization procedure.
{"title":"Mode pairing quantum key distribution with light source monitoring","authors":"Zhenhua Li, Tianqi Dou, Yuheng Xie, Weiwen Kong, Na Chen, Qi Zhao, Wenpeng Gao, Peizhe Han, Yuanchen Hao, Haiqiang Ma, Yang Liu, Jianjun Tang","doi":"10.1088/1367-2630/ad7493","DOIUrl":"https://doi.org/10.1088/1367-2630/ad7493","url":null,"abstract":"Mode pairing quantum key distribution (MP-QKD) overcomes the repeaterless bound without requiring phase locking and phase tracking. However, MP-QKD still assumes that the light source is trusted, which can present challenges in practical deployments and potentially introduce security vulnerabilities. In this paper, we propose a light source monitoring (LSM) scheme that guarantees the security of MP-QKD with the untrusted light sources. The simulation results demonstrate that, when considering untrusted light sources, the performance of MP-QKD with the LSM scheme remains nearly identical to that of ideal MP-QKD, even in the presence of the source fluctuations. Furthermore, we simplify some of the complex integration calculations involved in simulating the observed quantities of MP-QKD, which reduces the running time of the parameter optimization procedure.","PeriodicalId":19181,"journal":{"name":"New Journal of Physics","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214698","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 : 2024-09-09DOI: 10.1088/1367-2630/ad7634
Runai Quan, Huibo Hong, Xiao Xiang, Mingtao Cao, Xinghua Li, Baihong Li, Ruifang Dong, Tao Liu and Shougang Zhang
Quantum time transfer has emerged as a powerful technique, offering sub-picosecond precision and inherent security through the nonlocal temporal correlation property of energy-time entangled biphoton sources. In this paper, we demonstrate the inherent security advantage of quantum time transfer, and the utilization in detecting potential intercept-resend attacks. By investigating the impact of these attacks on the nonlocality identifier associated with nonlocal dispersion cancellation of energy-time entanglement, we establish a security threshold model for detecting intercept-resend attacks. Experimental verification on a 102 km fiber-optic link confirms that even a malicious delay as small as 25 ps can be identified. This investigation serves as a compelling illustration of secure two-way time transfer, safeguarding against intercept-resend attacks, and showcasing its potential applications in fields reliant on authentic time distribution between remote parties.
{"title":"Enhancing quantum time transfer security: detecting intercept-resend attacks with energy-time entanglement","authors":"Runai Quan, Huibo Hong, Xiao Xiang, Mingtao Cao, Xinghua Li, Baihong Li, Ruifang Dong, Tao Liu and Shougang Zhang","doi":"10.1088/1367-2630/ad7634","DOIUrl":"https://doi.org/10.1088/1367-2630/ad7634","url":null,"abstract":"Quantum time transfer has emerged as a powerful technique, offering sub-picosecond precision and inherent security through the nonlocal temporal correlation property of energy-time entangled biphoton sources. In this paper, we demonstrate the inherent security advantage of quantum time transfer, and the utilization in detecting potential intercept-resend attacks. By investigating the impact of these attacks on the nonlocality identifier associated with nonlocal dispersion cancellation of energy-time entanglement, we establish a security threshold model for detecting intercept-resend attacks. Experimental verification on a 102 km fiber-optic link confirms that even a malicious delay as small as 25 ps can be identified. This investigation serves as a compelling illustration of secure two-way time transfer, safeguarding against intercept-resend attacks, and showcasing its potential applications in fields reliant on authentic time distribution between remote parties.","PeriodicalId":19181,"journal":{"name":"New Journal of Physics","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214697","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 : 2024-09-06DOI: 10.1088/1367-2630/ad73fd
A V Maiorova, D Karlovets, S Fritzsche, A Surzhykov, Th Stöhlker
Coulomb excitation of hydrogen atoms by vortex protons is theoretically investigated within the framework of the non-relativistic first–Born approximation and the density matrix approach. Special attention is paid to the magnetic sublevel population of excited atoms and, consequently, to the angular distribution of the fluorescence radiation. We argue that both these properties are sensitive to the projection of the orbital angular momentum (OAM), carried by the projectile ions. In order to illustrate the OAM–effect, detailed calculations have been performed for the 1s→2p excitation and the subsequent 2p→1s radiative decay of a hydrogen target, interacting with incident Laguerre–Gaussian vortex protons. The calculation results suggest that Coulomb excitation can be employed for the diagnostics of vortex ion beam at accelerator and storage ring facilities.
{"title":"Coulomb excitation of hydrogen atoms by vortex ion beams","authors":"A V Maiorova, D Karlovets, S Fritzsche, A Surzhykov, Th Stöhlker","doi":"10.1088/1367-2630/ad73fd","DOIUrl":"https://doi.org/10.1088/1367-2630/ad73fd","url":null,"abstract":"Coulomb excitation of hydrogen atoms by vortex protons is theoretically investigated within the framework of the non-relativistic first–Born approximation and the density matrix approach. Special attention is paid to the magnetic sublevel population of excited atoms and, consequently, to the angular distribution of the fluorescence radiation. We argue that both these properties are sensitive to the projection of the orbital angular momentum (OAM), carried by the projectile ions. In order to illustrate the OAM–effect, detailed calculations have been performed for the <inline-formula>\u0000<tex-math><?CDATA $1s to 2p$?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:mn>1</mml:mn><mml:mi>s</mml:mi><mml:mo accent=\"false\" stretchy=\"false\">→</mml:mo><mml:mn>2</mml:mn><mml:mi>p</mml:mi></mml:mrow></mml:math><inline-graphic xlink:href=\"njpad73fdieqn1.gif\"></inline-graphic></inline-formula> excitation and the subsequent <inline-formula>\u0000<tex-math><?CDATA $2p to 1s$?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:mn>2</mml:mn><mml:mi>p</mml:mi><mml:mo accent=\"false\" stretchy=\"false\">→</mml:mo><mml:mn>1</mml:mn><mml:mi>s</mml:mi></mml:mrow></mml:math><inline-graphic xlink:href=\"njpad73fdieqn2.gif\"></inline-graphic></inline-formula> radiative decay of a hydrogen target, interacting with incident Laguerre–Gaussian vortex protons. The calculation results suggest that Coulomb excitation can be employed for the diagnostics of vortex ion beam at accelerator and storage ring facilities.","PeriodicalId":19181,"journal":{"name":"New Journal of Physics","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214700","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 : 2024-09-06DOI: 10.1088/1367-2630/ad748f
Nikolett Német, Árpád Kurkó, András Vukics, Péter Domokos
We present a superquantization rule which indicates the possible robust stationary states of a generic driven-dissipative quantum system. Multistability in a driven cavity mode interacting with a qudit is revealed hence within a simple intuitive picture. The accuracy of the superquantization approach is confirmed by numerical simulations of the underlying quantum model. In the case when the qudit is composed of several two-level emitters coupled homogeneously to the cavity, we demonstrate the robustness of the superquantized steady states to single-emitter decay.
{"title":"Superquantization rule for multistability in driven-dissipative quantum systems","authors":"Nikolett Német, Árpád Kurkó, András Vukics, Péter Domokos","doi":"10.1088/1367-2630/ad748f","DOIUrl":"https://doi.org/10.1088/1367-2630/ad748f","url":null,"abstract":"We present a superquantization rule which indicates the possible robust stationary states of a generic driven-dissipative quantum system. Multistability in a driven cavity mode interacting with a qudit is revealed hence within a simple intuitive picture. The accuracy of the superquantization approach is confirmed by numerical simulations of the underlying quantum model. In the case when the qudit is composed of several two-level emitters coupled homogeneously to the cavity, we demonstrate the robustness of the superquantized steady states to single-emitter decay.","PeriodicalId":19181,"journal":{"name":"New Journal of Physics","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214494","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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