Atomic physics: computer calculations and theoretical analysis

Casimir effects in atomic, molecular, and optical physics

The long-range interaction between two atoms and the long-range interaction between an ion and an electron are compared at small and large intersystem separations. The vacuum dressed atom formalism is applied and found to provide a framework for interpretation of the similarities between the two cases. The van der Waals forces or Casimir-Polder potentials are used to obtain insight into relativistic and higher multipolar terms.

Introducing many-body physics using atomic spectroscopy

Atoms constitute relatively simple many-body systems, making them suitable objects for developing an understanding of basic aspects of many-body physics. Photoabsorption spectroscopy is a prominent method to study the electronic structure of atoms and the inherent many-body interactions. In this article the impact of many-body effects on well-known spectroscopic features such as Rydberg series, Fano resonances, Cooper minima, and giant resonances is studied, and related many-body phenomena in other fields are outlined. To calculate photoabsorption cross sections the time-dependent configuratio…

Integration over spin-angular variables in atomic physics

A review of methods for finding general expressions for matrix elements (non-diagonal with respect to configurations included) of any one- and two-particle operator for an arbitrary number of shells in an atomic configuration is given. These methods are compared in various aspects, and the advantages or shortcomings of each particular method are discussed. Efficient method to find the abovementioned quantities in LS coupling is presented, based on the use of symmetry properties of operators and matrix elements in three spaces (orbital, spin and quasispin), second quantization in coupled tensor…

The hyperfine anomaly in heavy atoms and its role in precision atomic searches for new physics

We report on our calculations of differential hyperfine anomalies in the nuclear single-particle model for a number of atoms and ions of interest for studies of fundamental symmetries violations. Comparison with available experimental data allows one to discriminate between different nuclear magnetization models, and this data supports the use of the nuclear single-particle model over the commonly-used uniform ball model. Accurate modelling of the nuclear magnetization distribution is important for testing atomic theory through hyperfine comparisons. The magnetization distribution must be adeq…

Resolving all-order method convergence problems for atomic physics applications

The development of the relativistic all-order method where all single, double, and partial triple excitations of the Dirac-Hartree-Fock wave function are included to all orders of perturbation theory led to many important results for study of fundamental symmetries, development of atomic clocks, ultracold atom physics, and others, as well as provided recommended values of many atomic properties critically evaluated for their accuracy for large number of monovalent systems. This approach requires iterative solutions of the linearized coupled-cluster equations leading to convergence issues in so…

The impact of atomic precision measurements in high energy physics

In this talk I discuss the relevance of atomic physics in understanding some important questions about elementary particle physics. A particular attention is devoted to atomic parity violation measurements which seem to suggest new physics beyond the Standard Model. Atomic physics might also be relevant in discovering possible violations of the CPT symmetry.

Constraint on axion-like particles from atomic physics

A possibility to constrain axion-like particles from precision atomic physics is considered.

The Structure of Light Nuclei and Its Effect on Precise Atomic Measurements

My talk will consist of three parts: (a) what every atomic physicist needs to know about the physics of light nuclei [and no more]; (b) what nuclear physicists can do for atomic physics; (c) what atomic physicists can do for nuclear physics. A brief qualitative overview of the nuclear force and calculational techniques for light nuclei will be presented, with an emphasis on debunking myths and on recent progress in the field. Nuclear quantities that affect precise atomic measurements will be discussed, together with their current theoretical and experimental status. The final topic will be a d…

Relativistic Atomic Physics: from Atomic Clock Synchronization towards Relativistic Entanglement

A review is given of the implications of the absence of an intrinsic notion of instantaneous 3-space, so that a clock synchronization convention has to be introduced, for relativistic theories.

Otto Stern (1888-1969): The founding father of experimental atomic physics

We review the work and life of Otto Stern who developed the molecular beam technique and with its aid laid the foundations of experimental atomic physics. Among the key results of his research are: the experimental determination of the Maxwell-Boltzmann distribution of molecular velocities (1920), experimental demonstration of space quantization of angular momentum (1922), diffraction of matter waves comprised of atoms and molecules by crystals (1931) and the determination of the magnetic dipole moments of the proton and deuteron (1933).

Experimental methods of ultracold atomic physics

Experiments on solid-state materials and atomic quantum gases are increasingly investigating similar concepts in many-body quantum physics. Yet, the flavor of experiments on the gaseous atomic materials is different from that of conventional materials research. Here, we summarize some aspects of atomic physics and some of the common technical elements of cold-atom experiments which underlie the investigations described in the remaining chapters of this volume.

Using Quantum Coherence to Enhance Gain in Atomic Physics

Quantum coherence and interference effects in atomic and molecular physics has been extensively studied due to intriguing counterintuitive physics and potential important applications. Here we present one such application of using quantum coherence to generate and enhance gain in extreme ultra-violet(XUV)(@58.4nm in Helium) and infra-red(@794.76nm in Rubidium) regime of electromagnetic radiation. We show that using moderate external coherent drive, a substantial enhancement in the energy of the lasing pulse can be achieved under optimal conditions. We also discuss the role of coherence. The pr…

Majorana: from atomic and molecular, to nuclear physics

In the centennial of Ettore Majorana's birth (1906-1938?), we re-examine some aspects of his fundamental scientific production in atomic and molecular physics, including a not well known short communication. There, Majorana critically discusses Fermi's solution of the celebrated Thomas-Fermi equation for electron screening in atoms and positive ions. We argue that some of Majorana's seminal contributions in molecular physics already prelude to the idea of exchange interactions (or Heisenberg-Majorana forces) in his later workson theoretical nuclear physics. In all his papers, he tended to emph…

Precision Atomic Physics Techniques for Nuclear Physics with Radioactive Beams

Atomic physics techniques for the determination of ground-state properties of radioactive isotopes are very sensitive and provide accurate masses, binding energies, Q-values, charge radii, spins, and electromagnetic moments. Many fields in nuclear physics benefit from these highly accurate numbers. They give insight into details of the nuclear structure for a better understanding of the underlying effective interactions, provide important input for studies of fundamental symmetries in physics, and help to understand the nucleosynthesis processes that are responsible for the observed chemical a…

A new physical mechanism for the onset of atomic ionization in an optical field with jolts of phase

A theoretical model that describes a new mechanism of atomic and molecular ionization in a low intensity electro-magnetic wave (light or laser beam) with the energy of quanta that is lower than required for a single photon ionization is presented. The essence of the proposed physical mechanism is the step-like gain of energy of a bound electron that occurs every time the phase of the electro-magnetic field jolts. Providing there is sufficiently large number of the phase jolts, the summation of the step increases of the electron oscillation energy can render the total energy of the bound electr…

百瓦级注入锁频二极管激光系统用于原子物理

Watt-class injection-locked diode laser system at 399 nm for atomic physics

本文展示了一种399纳米、输出功率达1瓦的注入锁频激光系统，通过单模外部腔二极管激光器提供5毫瓦种子功率，实现了频率敏捷性和线宽继承，用于原子物理中的钇原子束光谱学研究。

Accurate abundance analysis of late-type stars: advances in atomic physics

The measurement of stellar properties such as chemical compositions, masses and ages, through stellar spectra, is a fundamental problem in astrophysics. Progress in the understanding, calculation and measurement of atomic properties and processes relevant to the high-accuracy analysis of F-, G-, and K-type stellar spectra is reviewed, with particular emphasis on abundance analysis. This includes fundamental atomic data such as energy levels, wavelengths, and transition probabilities, as well as processes of photoionisation, collisional broadening and inelastic collisions. A recurring theme thr…

Ground Control to Niels Bohr: Exploring Outer Space with Atomic Physics

We provided an introduction to transition state theory and the connections it provides between atomic and celestial physics. We include brief discussions of historical background, recent applications in space mission design, and current research efforts.

Microwave sidebands for atomic physics experiments by period one oscillation in optically injected diode lasers

We show that nonlinear dynamics in diode lasers with optical injection leads to frequency tunable microwave sidebands which are suitable for atomic physics experiments. We demonstrate the applicability of the sidebands in an experiment where rubidium atoms are magneto-optically trapped with both the trap and the re-pump optical frequencies derived from one optically injected laser. We find linewidth narrowing in the optical spectrum of the injected laser at both the injection frequency and the sideband frequency. With strong optical injection which leads to frequency locking we find a complete…

分形原子物理：关于分形空间中原子稳定性与瑞利德态的邀请

Fractatomic Physics: An Invitation with Atomic Stability and Rydberg States in Fractal Spaces

本文提出分形原子物理的概念，探讨分形空间中原子的稳定性及瑞利德态特性，揭示其在诱导强纠缠和长程多体相互作用中的潜力。

Comment on "New physics constraints from atomic parity violation in 133-Cs"

In a recent Letter [B. K. Sahoo, B. P. Das, and H. Spiesberger, Phys. Rev. D 103, L111303 (2021)], a calculation of the parity violating 6S-7S E1 amplitude in Cs is reported, claiming an uncertainty of just 0.3%. In this Comment, we point out that key contributions have been omitted, and the theoretical uncertainty has been significantly underestimated. In particular, the contribution of missed QED radiative corrections amounts to several times the claimed uncertainty.

原子铒玻色-爱因斯坦凝聚体合成维度中的手性边缘动力学与量子霍尔物理

Chiral edge dynamics and quantum Hall physics in synthetic dimensions with an atomic erbium Bose-Einstein condensate

本研究利用铒原子玻色-爱因斯坦凝聚体在合成维度中实现了二维合成霍尔系统，观测到手性边缘电流，并通过局部陈标记验证了其拓扑性质，为冷原子系统中的拓扑相研究提供了新平台。

物理教学实验笔记：铷原子光谱学

Notes from the Physics Teaching Lab: Rubidium Atomic Spectroscopy

本文详细介绍了使用Teachspin二极管激光光谱仪进行铷光谱实验的方法，包括测量和数据分析示例，旨在辅助教学课程设计。

Constraints on a long-range spin-independent interaction from precision atomic physics

Constraints on a spin-independent interaction by exchange of a neutral light boson are derived from precision data on the electron anomalous magnetic moment and from atomic spectroscopy of hydrogen and deuterium atoms. The mass range from $1 $eV$/c^2$ to $1 $Mev$/c^2$ is studied and the effective coupling constant $α^\prime$ is allowed below the level of $10^{-11} - 10^{-13}$ depending on the value of the boson mass. The mass range corresponds to the Yukawa radius from 0.0002 nm to 20 nm, which covers the distances far above and far below the Bohr radius of the hydrogen atom.

A flexible control system for atomic, molecular and optical physics experiments

We have implemented a control system for experiments in atomic, molecular and optical physics based on a commercial low-cost board, featuring a field-programmable gate array as part of a system-on-a-chip on which a Linux operating system is running. The board features Gigabit Ethernet, allowing for fast data transmission and operation of remote experimental systems. A single board can control a set of devices generating digital, analog and radio frequency signals with a precise timing given either by an external or internal clock. Contiguous output and input sampling rates of up to 40 MHz are …

Programmable System on Chip for controlling an atomic physics experiment

Most atomic physics experiments are controlled by a digital pattern generator used to synchronize all equipment by providing triggers and clocks. Recently, the availability of well-documented open-source development tools has lifted the barriers to using programmable systems on chip (PSoC), making them a convenient and versatile tool for synthesizing digital patterns. Here, we take advantage of these advancements in the design of a versatile clock and pattern generator using a PSoC. We present our design with the intent of highlighting the new possibilities that PSoCs have to offer in terms of…

Tapered-amplified AR-coated laser diodes for Potassium and Rubidium atomic-physics experiments

We present a system of room-temperature extended-cavity grating-diode lasers (ECDL) for production of light in the range 760-790nm. The extension of the tuning range towards the blue is permitted by the weak feedback in the cavity: the diodes are anti-reflection coated, and the grating has just 10% reflectance. The light is then amplified using semiconductor tapered amplifiers to give more than 400mW of power. The outputs are shown to be suitable for atomic physics experiments with potassium (767nm), rubidium (780nm) or both, of particular relevance to doubly-degenerate boson-fermion mixtures.

ElecSus: A program to calculate the electric susceptibility of an atomic ensemble

We present a computer program and underlying model to calculate the electric susceptibility of a gas, which is essential to predict its absorptive and dispersive properties. Our program focusses on alkali-metal vapours where we use a matrix representation of the atomic Hamiltonian in the completely uncoupled basis in order to calculate transition frequencies and strengths. The program calculates various spectra for a weak-probe laser beam in an atomic medium with an applied axial magnetic field. This allows many optical devices to be designed, such as Faraday rotators/filters, optical isolator…

Empirical determination of the Bohr-Weisskopf effect in cesium and improved tests of precision atomic theory in searches for new physics

The finite distribution of the nuclear magnetic moment across the nucleus gives a contribution to the hyperfine structure known as the Bohr-Weisskopf (BW) effect. We have obtained an empirical value of -0.24(18)% for this effect in the ground and excited s states of atomic Cs-133. This value is found from historical muonic-atom measurements in combination with our muonic-atom and atomic many-body calculations. The effect differs by 0.5% in the hyperfine structure from the value found using the uniform magnetization distribution, which has been commonly employed in the precision heavy-atom comm…

A novel time-of-flight mass spectrometer using radial extraction from a linear quadrupole trap for atomic, molecular, and chemical physics

We demonstrate the implementation of a simple time-of-flight (ToF) mass spectrometer with medium-mass resolution ($m/Δm\sim50$) geared towards the demands of atomic, molecular, and chemical physics experiments. By utilizing a novel radial ion extraction scheme from a linear quadrupole trap, a device with large trap capacity and high optical access is realized without sacrificing mass resolution. Here we describe the construction and implementation of the device as well as present representative ToF spectra. We conclude by demonstrating the flexibility of the device with proof-of-principle expe…

Probing new physics using Rydberg states of atomic hydrogen

We consider the role of high-lying Rydberg states of simple atomic systems such as $^1$H in setting constraints on physics beyond the Standard Model. We obtain highly accurate bound states energies for a hydrogen atom in the presence of an additional force carrier (the energy levels of the Hellmann potential). These results show that varying the size and shape of the Rydberg state by varying the quantum numbers provides a way to probe the range of new forces. By combining these results with the current state-of-the-art QED corrections, we determine a robust global constraint on new physics tha…

利用原子钟进行量子传感用于核物理和粒子物理

Quantum Sensing Using Atomic Clocks for Nuclear and Particle Physics

利用原子钟的高精度量子传感技术，用于探测核物理和粒子物理中微弱相互作用的新型研究领域。