Atomic physics is the field of physics that studies atoms as an isolated system of electrons and an atomic nucleus. It is primarily concerned with the arrangement of electrons around the nucleus and the processes by which these arrangements change. This includes ions as well as neutral atoms and, ...

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Thermionic emission, delayed emission and predissociation

In molecular photodissociation, the thermionic emission, delayed emission and predissociation are the same? otherwise, what is the difference between them? My question is not about the solids, but I ...
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262 views

How is a Rydberg Blockade Radius defined?

Rydberg blockade is a phenomena in 3 or more level systems of Rydberg dressed atoms.
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57 views

friction on atomic scale

I am getting into friction on an atomic scale. For instance, take two rigid layers of atoms of the kind A that are placed on top of each other, just like putting two boards of wood on top of each ...
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36 views

Where can I find the Bohr Sommerfield condition?

I need to solve the Hydrogen Atom using the phase integral [Bohr Sommerfield Condition] but I don't know where can I find it. Help me please!
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53 views

Where do electrons get the energy to remain in orbit? [duplicate]

As we know electrons continuously revolve around the nuclus without falling in it at a high velocity beating it's force of attraction. My question is where do electrons get energy to revolve around ...
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2answers
64 views

Optical trapping problem

Can we make light slower by applying optical trapping (I mean applying laser beam to lower the speed of light)?
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82 views

Gravity's limits

Suppose there are only two hydrogen atoms in the entire universe. Suppose further that they are both situated at the very limits of the cosmos, equally distant. Would they exert an attractive force on ...
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169 views

Thermionic emission and delayed emission

I want to understand the concepts behind the thermionic emission. In thermionic emission, the energy randomization occurs and the energy may be split to electronic or roto-vibrational states. If this ...
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1answer
171 views

What is the height of the electron orbits of an atom?

What are the heights of the electron orbits of an atom? (How far apart are the energy levels of the electron relative to the center of the atomic nucleus?) How fast do electrons move in their orbits?
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170 views

What will happen if a ground state hydrogen atom is placed in a low frequency, but high intensity laser field?

Similar questions have been asked before, but this one extends the scope of interpretation and applications. Let us ask the question: What will happen if we have a laser gun that produces a high ...
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2answers
4k views

Frequency of an Electron

My question is very simple. If frequency is defined as the cylces per unit time, Then what is meant by "Frequency of an Electron" ? If the rotation of electron around a nucleus is considered then, ...
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207 views

Is the photon energy required to cause an atomic transition $\Delta E+\Delta KE$, where $\Delta E$ is the “transition energy”?

An atom "at rest" can absorb a photon, and while some of this energy goes into increasing the energy level of the electron, momentum must be conserved, and so some energy must also increase the ...
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If photon energies are continuous and atomic energy levels are discrete, how can atoms absorb photons?

If photon energies are continuous and atomic energy levels are discrete, how can atoms absorb photons? The probability of a photon having just the right amount of energy for an atomic transition is ...
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74 views

Where to find probability density plots for all elements?

Does anyone know where I can find something similar to this, but for all elements? I would love to find something with the same image quality. Also, is there any software that can produce images ...
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338 views

Why it is called a Newton Sphere? (Velocity map imaging)

In velocity map imaging (photo-dissociation and photo-emission), the ejected particles form a newton sphere. I didn't really get the concept why it is called a "newton sphere" and also why at the ...
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153 views

Does the electron have spin in it's own reference frame?

In our atomic physics class, we saw that the spin-orbit coupling term arises from the scalar product of the magnetic moment of the electron (proportional to its spin), and the magnetic field created ...
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3answers
1k views

What is the physical meaning/concept behind Legendre polynomials?

In mathematical physics and other textbooks we find the Legendre polynomials are solutions of Legendre's differential equations. But I didn't understand where we encounter Legendre's differential ...
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3answers
246 views

Do electrons in multi-electron atoms really have definite angular momenta?

Since the mutual repulsion term between electrons orbiting the same nucleus does not commute with either electron's angular momentum operator (but only with their sum), I'd assume that the electrons ...
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84 views

Optimal methods for mapping out molecules, atoms and nuclei and their energy levels?

I'm wondering if it would be possible to map out all the different types of molecules, atoms and nuclei and their energy levels on one page (even if in a generalised way)? But perhaps I'm referring to ...
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1answer
760 views

Explanation of energy levels in molecules, atoms, nuclei and their relationship

Why are the energy levels of molecules, the atoms that form them and the nuclei inside the atoms considered separately? Or phrased in a different way- what is it that makes their energy levels so ...
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1answer
232 views

Rutherford's Gold Foil Experiment

Can anybody explain how Rutherford bombarded a 0.0004 cm thick gold foil? How did he put it in a photographic sheet? Wasn't the foil too thin to be held? How did he know that the atoms were deflected ...
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2answers
180 views

Causality in a gedanken experiment on the hydrogen atom

Consider a gedanken(=thought) experiment where I am tracking the motion of the electron in a hydrogen atom with a time resolution of (say) $\Delta t = 10^{-20}$ seconds. Further assume (for ...
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1answer
352 views

Explanation on Atomic Orbitals and Molecular Orbitals

We were reading about atomic structures and bond making and my teacher told me that when two atoms are fused or when they make bond, two orbitals are formed. 1-Bonding Molecular Orbital & 2- ...
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2answers
241 views

Is the artificial gauge field a gauge field?

The so-called artificial gauge fields are actually the Berry connection. They could be $U(1)$ or $SU(N)$ which depends on the level degeneracy. For simplicity, let's focus on $U(1)$ artificial gauge ...
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163 views

General question on aligning a quantization axis

I have a general question on how to work with quantization axis. Here is the setup: I am looking at a single two-level atom placed at the origin $(0, 0, 0)$, which is unperturbed in the sense that ...
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350 views

Spin-orbit coupling constant for rubidium

I have come across the following question in my course notes: The $5s\to 5p$ transition in rubidium is split into two components with wavelengths of 780nm and 795nm respectively. For the $5p$ state, ...
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162 views

About Efimov States and Halo-Nuclei

I read that Halo nuclei could be seen as special Efimov states, depending on the subtle definitions. (The last sentence in the second to last paragraph of this Wikipedia article.) This does ...
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2answers
285 views

high spin atoms SU(2) representation

I am very confused that some atoms called high spin or magnetic atoms have spin level more than $\frac{1}{2}$ but are still said to have $SU(2)$ symmetry. Why not $SU(N)$?
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82 views

Why, in EXAFS spectrum, does the absorption coefficient monotonically decrease with increasing photon energy?

In atomic physics, it is common knowledge that following the absorption edge, where the photon energy equals the binding energy of a core electron, a monotonic decrease in the absorption coefficient ...
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471 views

Is the structural similarity between atoms ( smallest) and universe (biggest) a conincidence. Or there can a reason for this beyond imaginations

Is the structural similarity between atoms ( smallest) and universe (biggest) a coincidence? Or there can a reason for this beyond imaginations? It seems like, if one starts travelling out from ...
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0answers
192 views

What is the Landé g factor?

What is the Landé g factor? I know that it gives the relation between magnetic moment and angular moment, but i wanted to know why are those magnitudes related to each other and why is the magnetic ...
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3answers
447 views

Disproving a refutation of quantum mechanics (QM) via a calculation of the ground state of the helium atom

This website http://www7b.biglobe.ne.jp/~kcy05t/ appears to refute Quantum mechanics using some proof. An important paper involved is this 'Calculation of Helium Ground State Energy by Bohr's ...
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2answers
488 views

How robust is Kramers degeneracy in real material?

Kramers theorem rely on odd total number of electrons. In reality, total number of electrons is about 10^23. Can those electrons be so smart to count the total number precisely and decide to form ...
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1answer
96 views

What are relativistic and radiative effects (in quantum simulation)?

I'm reading about Quantum Monte Carlo, and I see that some people are trying to calculate hydrogen and helium energies as accurately as possible. QMC with Green's function or Diffusion QMC seem to be ...
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382 views

Why is there a factor of 1/2 in the interaction energy of an induced dipole with the field that induces it?

In this paper, there's the following sentence: ...and the factor 1/2 takes into account that the dipole moment is an induced, not a permanent one. Without any further explanation. I looked ...
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718 views

What exactly is a Fluorescent lamp?

A fluorescent tube (home-based) works on the principle of discharge of electricity through gases, as far as I can tell (I don't know much about cathode rays or gas discharge) What happens inside the ...
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4answers
4k views

Why do covalent bonds form?

why in a covalent bond are "the bonded electrons are in a lower energy state than if the individual atoms held them at the same proximity"? Also is it correct that " I think when you start pushing ...
6
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1answer
1k views

Darwin term and Zitterbewegung

I've noticed that in the discussion of the fine structure of Hydrogen atom standard QM texts claim that the Darwin term, which corrects energy of $\ell=0$ (or $s$-) states only, is related to the ...
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3answers
195 views

In solving the hydrogen atom, how to see intuitively in advance that the spin effects to the energy spectrum can be ignored?

When the hydrogen atom is solved in QM books spin is usually ignored because its effect is to add tiny piece to the energy. My question is, is there a way to see this in advance, to see that if we ...
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3answers
235 views

How can we be sure about the constancy of atomic clocks as in the Hafele and Keating time dilation test?

Atomic clocks were used in Hafele and Keatings experiment which supposedly helped to prove time dilation. Time Dilation Proof - Hafele and Keating How can we be sure other forces didn't act upon the ...
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1answer
374 views

Why and how is nondegenerate perturbation theory used for time evolution under $\vec{L}.\vec{S}$ coupling?

Let us say that we start with an electron which is in a spin up state and has a spatial wave-function of the form $xf(r)$. Then one turns on a perturbation of the form ...
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5answers
808 views

What do we actually mean when we say that matter is a wave?

What do we actually mean when we say that matter is a wave? What does the wavelength of this matter wave indicate? The idea of a particle behaving like a wave is kinda incomprehensible to me. ...
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187 views

What is electron momentum density in solids and molecules?

Can someone kindly help me to know how can i get electron momentum density for one orbital like home? what is the theory of electron momentum density? how can I derive electron momentum density from ...
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2answers
723 views

Is there a list of all atomic electron state transitions and the corresponding radiation emitted?

Here's a quote from Wikipedia: As an example, the ground state configuration of the sodium atom is 1s22s22p63s, as deduced from the Aufbau principle (see below). The first excited state is ...
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3answers
1k views

What keeps electrons in an atom from flying away or falling into the nucleus?

In atoms, what force or charge, etc. keeps electrons from flying away or into their nucleus? is there a kind of weak-force at work on the atomic scale? Note I am aware the electron positions are ...
6
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4answers
883 views

Intrinsic structure of electron

The electron contains finite negative charge.The same charges repel each other.What makes electron stable and why does it not burst? Is it a law of nature that the electron charge is the smallest ...
4
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1answer
235 views

Why is Mosely screening in heavy atom K-shell 1 unit?

The Wikipedia article on Moseley's law seems to show that the screening of heavy atoms is by 1 electron charge exactly (in the limit of large Z, experimental precision, within nonrelativistic limits, ...
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2answers
491 views

Implementing simple atom model using density functional theory (DFT)

I am trying to write computer code which will find the energy and density function for an atom with $Z$ protons and $N$ electrons. I am working in 1D for simplicity and would like to make the overall ...
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Why are noble gases used for lights?

I know that neon is used in advert signs due to its inertness. However, I am not entirely sure how the inertness is exploited. I think it is because Ne being inert means that after electricity frees ...
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1answer
647 views

Is Palladium an exception?

I have been taught in school that atoms cannot have more than 8 electrons in the outer shell. Palladium atom's electron configuration is 2,8,18,18. Why isn't it 2,8,18,17,1 like the case of Platinum ...