Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

College Physics

A way of deducing two-level atom's spontaneous emission

Luo Yun-wen

Published Jan 1, 2012• 0 citations
OpenAlex

Abstract

An equation for describing interaction of atom and vacuum fluctuation is proposed,because the energy of vacuum fluctuation is negative.It can get the probability of atoms in the excited state changing with time.The relation between the atom's spontaneous emission and the strength of vacuum fluctuation is discussed.

Related papers

Local aspects of disentanglement induced by spontaneous emission

Anna Jamróz

We consider spontaneous emission of two two-level atoms interacting with vacuum fluctuations. We study the process of disentanglement in this system and show the possibility of changing disentanglement time by local unitary operations.

arXiv:quant-ph/0602128•Journal of Physics A Mathematical and General•May 31, 2006•54 citations

A Quasi-Probability Approach to the Co-operative Spontaneous Emission

Kensuke S. Ikeda, H. Ito

The dynamics of the co-operative spontaneous emission from many two-level atoms is investigated by introducing a specific form of quasi-probability distribution which apparently excludes the vacuum fluctuation of the radiation field but includes the fluctuation of the atomic dipole moment. It is shown that the equation of motion for the random variables associated with the atom-field coupled system can be written in a quite classical form. As a result, the formula is derived for computing the multi-time correlation functions of the radiation field–essential to its coherence properties–which generalizes Bonifacio, Schwendimann and Haake's adiabatic “corresponding theorem”.

Progress of Theoretical Physics•Sep 1, 1975•7 citations

Intensity Fluctuations in Many-Atom Spontaneous Emission

Elisabeth Ressayre, Andree A. Tallet

The normalized two-time intensity-fluctuation functions are calculated for the spontaneous-emission radiation from a system of $N$ two-level atoms. The radiated field, when the system decays from the excited state to the ground state, does not look like a Gaussian or a coherent field.

Physical Review A•Mar 1, 1972•2 citations

Cavity quantum electrodynamics

Partha Ghose

Introduction Ever since 1916/17 when Einstein argued [45] [46] that spontaneous emission must occur if matter and radiation are to achieve thermal equilibrium, physicists have believed that spontaneous emission is an inherent quantum mechanical property of atoms and that excited atoms inevitably radiate. This view, however, overlooks the fact that spontaneous emission is a consequence of the coupling of quantized energy states of atoms with the quantized radiation field, and is a manifestation of quantum noise or of emission ‘stimulated’ by ‘vacuum fluctuations’. An infinity of vacuum states is available to the photon radiated by an excited atom placed in free space, leading to the effective irreversibility of such emissions. If these vacuum states are modified, as for example by placing an excited atom between closely spaced mirrors or in a small cavity (essentially the Casimir effect), spontaneous emission can be greatly inhibited or enhanced or even made reversible. Recent advances in atomic and optical techniques have made it possible to control and manipulate spontaneous emission. A whole new branch of quantum optics called ‘cavity QED’ has developed since 1987 utilizing these dramatic changes in spontaneous emission rates in cavities to construct new kinds of microscopic masers or micromasers that operate with a single atom and a few photons or with photons emitted in pairs in a two-photon transition.

Cambridge University Press eBooks•Apr 29, 1999•0 citations

Quantum Optics of Accelerated 2-level Systems on Arbitrary Stationary Trajectories

Jürgen Audretsch

Recently, a new physical picture for the spontaneous excitation of a uniformly accelerated two-level atom has been put forward [1]. Following a quantum optical approach it is based on the distinction of the two competing mechanisms which operate to excite an atom in the quantum vacuum: vacuum fluctuations and radiation reaction. Vacuum fluctuations tend to excite an atom in its ground state and de-excite it in an excited state. On the other hand, radiation reaction leads always to a loss of internal excitation energy. For an inertial atom in the ground state, the two contributions cancel exactly, so that a very sublime balance between vacuum fluctuations and radiation reaction prevents the spontaneous excitation of the atom [2]. If the atom is in the excited state, both contribution add up to the well-known spontaneous emission rate. It has been shown in [1] that uniform acceleration will disturb this balance. Spontaneous transitions from the ground state to the excited state become possible: the Unruh effect [3].

Teubner-Texte zur Physik•Jan 1, 1996•0 citations

Spontaneous Emission Spectra of an Atom in a Dissipative Cavity

Wei Su

The emission spectra of a two-level atom interacting with a single mode vacuum initial field in a dissipative cavity are investigated.A general expression for the emission spectrum is derived.The influences of the damping constant κ and the interaction time T on the atomic emission spectra are discussed.It is found that the relative height of pecks start to decrease with increasing κ.Only the interaction time being appropriate,the quantum characteristics of the spectrum can be observed.

Acta Sinica Quantum Optica•Jan 1, 2010•0 citations
The dynamics of the co-operative spontaneous emission from many two-level atoms is investigated by introducing a specific form of quasi-probability distribution which apparently excludes the vacuum fluctuation of the radiation field but includes the fluctuation of the atomic dipole moment. It is shown that the equation of motion for the random variables associated with the atom-field coupled system can be written in a quite classical form. As a result, the formula is derived for computing the multi-time correlation functions of the radiation field–essential to its coherence properties–which generalizes Bonifacio, Schwendimann and Haake's adiabatic “corresponding theorem”.
The normalized two-time intensity-fluctuation functions are calculated for the spontaneous-emission radiation from a system of NNN two-level atoms. The radiated field, when the system decays from the excited state to the ground state, does not look like a Gaussian or a coherent field.
Introduction Ever since 1916/17 when Einstein argued [45] [46] that spontaneous emission must occur if matter and radiation are to achieve thermal equilibrium, physicists have believed that spontaneous emission is an inherent quantum mechanical property of atoms and that excited atoms inevitably radiate. This view, however, overlooks the fact that spontaneous emission is a consequence of the coupling of quantized energy states of atoms with the quantized radiation field, and is a manifestation of quantum noise or of emission ‘stimulated’ by ‘vacuum fluctuations’. An infinity of vacuum states is available to the photon radiated by an excited atom placed in free space, leading to the effective irreversibility of such emissions. If these vacuum states are modified, as for example by placing an excited atom between closely spaced mirrors or in a small cavity (essentially the Casimir effect), spontaneous emission can be greatly inhibited or enhanced or even made reversible. Recent advances in atomic and optical techniques have made it possible to control and manipulate spontaneous emission. A whole new branch of quantum optics called ‘cavity QED’ has developed since 1987 utilizing these dramatic changes in spontaneous emission rates in cavities to construct new kinds of microscopic masers or micromasers that operate with a single atom and a few photons or with photons emitted in pairs in a two-photon transition.
Recently, a new physical picture for the spontaneous excitation of a uniformly accelerated two-level atom has been put forward [1]. Following a quantum optical approach it is based on the distinction of the two competing mechanisms which operate to excite an atom in the quantum vacuum: vacuum fluctuations and radiation reaction. Vacuum fluctuations tend to excite an atom in its ground state and de-excite it in an excited state. On the other hand, radiation reaction leads always to a loss of internal excitation energy. For an inertial atom in the ground state, the two contributions cancel exactly, so that a very sublime balance between vacuum fluctuations and radiation reaction prevents the spontaneous excitation of the atom [2]. If the atom is in the excited state, both contribution add up to the well-known spontaneous emission rate. It has been shown in [1] that uniform acceleration will disturb this balance. Spontaneous transitions from the ground state to the excited state become possible: the Unruh effect [3].