Cooperative effect in the radiation process has been studied in for more than half a
century. It is important in the sense of both basic physics and applied science.
In this work, we study the dynamics of the cooperative spontaneous emission
from an ensemble of N atoms which is uniformly excited by absorbing a single photon.
We reveal that there are two different regimes in which the system exhibits
totally different behaviors. One of them is the superradiance type of behavior: the
system decays much quicker than single atom decay, with a decay rate proportional
to N(λ/R)2, where N is the atom numbers, R is the size of the atom cloud, and λ
is the wavelength. We call it Markovian regime because the sytem does not persist
memory effect. The other regime is called non-Markovian regime and the system oscillates
with effective Rabi oscillation frequency
while slowly decaying with a rate
proportional to the photon escaping rate. The effective Rabi oscillation is a new type
of dynamics which analogs well known Cavity QED behavior.
Particularly in the Markovian regime, we study the system dynamics as a manybody
eigenfunction and eigenvalue problem. For a dense cloud, we find analytical solutions for the eigenstates and corresponding eigenvalues, which can help to generally
describe the system dynamics for any initial conditions in this regime.
One of the applications is in atom microscopy. We propose a scheme to measure
the distance between two atoms/molecules beyond diffraction limit. It covers the
whole range from half the wavelength to sub-nanometers, utilizing both the atom
localization technique and the collective frequency shift effect due to the cooperative
effect in the radiation of the two atoms.
Another application that we propose is to generate Coherent XUV radiation using
Raman-type superradaince. We prove that intense short pulses of XUV radiation can
be produced by Raman type superradiance from an ensemble of atoms/ions driven
by visible or IR laser pulses.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-3226 |
| Date | 15 May 2009 |
| Creators | Chang, Juntao |
| Contributors | Scully, Marlan O., Zubairy, M. Suhail |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Dissertation, text |
| Format | electronic, application/pdf, born digital |
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