# Decoherence in Excited Atoms by Low-Energy Scattering

^{*}

## Abstract

**:**

## 1. Introduction

## 2. Decoherence by Scattering

## 3. Function of the Perturbation

## 4. Temporal Evolution

#### 4.1. Photon Scattering

#### 4.2. Massive Particle Scattering

## 5. Conclusions

## Acknowledgments

## Author Contributions

## Conflicts of Interest

## References

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**Figure 1.**Coefficients of the eigenstate decomposition of the atomic state after the scattering of a particle by the nucleus (Equation (1)) for different values of nuclear displacement. The initial state of the atom has no angular momentum, and principal quantum number ${n}_{0}=10$.

**Figure 2.**Probability of finding the atom in the initial state after a particle scattering by the nucleus as a function of the principal quantum number for different transmitted energies. The used mass for nucleus was ${m}_{N}=1.66\times {10}^{-27}$ kg, which is approximately the mass of a Rubidium-87 nucleus.

**Figure 3.**Difference in the population of the initial state of an atom with ${n}_{0}=60$ and ${m}_{N}=1.66\times {10}^{-27}$ kg as a function of time. The plots correspond to the scattering of (

**a**) solar radiation (${\eta}_{E}=8.49$ MeV/cm${}^{3}$); (

**b**) ambient lights in the laboratory (${\eta}_{E}=1.17$ KeV/cm${}^{3}$); and (

**c**) the cosmic microwave background (${\eta}_{E}=0.25$ eV/cm${}^{3}$).

**Figure 4.**Difference in the initial state of an atom with ${n}_{0}=60$ and ${m}_{N}=1.66\times {10}^{-27}$ kg as a function of time. The plots correspond to the interaction with (

**1**) neutrons from secondary cosmic rays, and (

**2**) local Dark Matter composed of Axions.

© 2016 by the authors; licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC-BY) license (http://creativecommons.org/licenses/by/4.0/).

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**MDPI and ACS Style**

Quiñones, D.A.; Varcoe, B.
Decoherence in Excited Atoms by Low-Energy Scattering. *Atoms* **2016**, *4*, 28.
https://doi.org/10.3390/atoms4040028

**AMA Style**

Quiñones DA, Varcoe B.
Decoherence in Excited Atoms by Low-Energy Scattering. *Atoms*. 2016; 4(4):28.
https://doi.org/10.3390/atoms4040028

**Chicago/Turabian Style**

Quiñones, Diego A., and Benjamin Varcoe.
2016. "Decoherence in Excited Atoms by Low-Energy Scattering" *Atoms* 4, no. 4: 28.
https://doi.org/10.3390/atoms4040028