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Bound and resonance states of quantum dots play a significant role in photo-absorption processes. In this work, we analyze a cylindrical quantum dot, its spectrum and, in particular, the behaviour of the lowest resonance state when a…

Mesoscale and Nanoscale Physics · Physics 2014-05-01 Alba Y Ramos , Omar Osenda

We report an observation of a 148-fold suppression of resonant absorption of 14.4-keV photons from exp(-5.2) to exp(-0.2) with preservation of their spectral and temporal characteristics in an ensemble of the resonant two-level Fe-57 nuclei…

Fluctuations in light absorption by atoms are observed by applying laser light on rubidium atoms and measuring the transmitted light intensity fluctuations. These fluctuations are spontaneous noise, which are generic to photon atom…

Atomic Physics · Physics 2015-06-12 Takahisa Mitsui , Kenichiro Aoki

We consider a coherent state of light propagating through an ensemble of two-level atoms where all the atoms are initially in their ground state. In ordinary absorption, the transition of atoms to their excited state along with the…

Quantum Physics · Physics 2019-07-31 I. C. Nodurft , R. A. Brewster , T. B. Pittman , J. D. Franson

We develop a microscopic theory of the scattering, transmission, and sticking of 4He atoms impinging on a superfluid 4He slab at near normal incidence, and inelastic neutron scattering from the slab. The theory includes coupling between…

Condensed Matter · Physics 2009-10-31 C. E. Campbell , E. Krotscheck , M. Saarela

We revisit the photoabsorption from the ground state of Na, ending below and above the ionization threshold, with special emphasis on the shape of the photoionization cross section around the Cooper minimum. The present treatment, using a…

Atomic Physics · Physics 2022-12-02 Constantine E. Theodosiou

We observe time-correlated four photons within a correlation window of 20ns from spontaneous four-wave mixing via a double-Lambda scheme in a cold cloud of Rb-87 atoms. In contrast to high-power pulsed pumping of chi^(2) nonlinear processes…

This letter presents an analysis of the infrared ($\sim 3-28\,\mu m$) spectra extracted from the nuclear ($r < 150$ pc) regions of four low-luminosity active galactic nuclei (AGN), observed by JWST NIRSpec/IFU and MIRI/MRS as an extension…

Absorption of a photon by an electron moving parallel to a rough surface is studied.In the weak scattering regime we have evaluated the absorption probability of absorption of a single photon. It is shown the absorption probability with…

Mesoscale and Nanoscale Physics · Physics 2015-06-17 Zh. S. Gevorkian , V. Gasparian

This paper presents a nonperturbative treatment of strong-coupling induced effects in atom-field systems which cannot be seen in traditional perturbative treatments invoking compromising assumptions such as the Born-Markov, rotating wave or…

Quantum Physics · Physics 2020-02-25 Jen-Tsung Hsiang , Bei-Lok Hu

The positive effects of various perturbations introduced in a bidimensional photonic-crystal patterned membrane on its integrated absorption are investigated numerically and theoretically. Two phenomena responsible for the enhanced…

Electromagnetically induced absorption (EIA) was observed on a sample of $% ^{85}Rb$ in a magneto-optical trap using low intensity cw copropagating pump and probe optical fields. At moderate trapping field intensity, the EIA spectrum is…

Atomic Physics · Physics 2016-09-08 A. Lipsich , S. Barreiro , P. Valente , A. Lezama

The optical absorption of a single spherical semiconductor quantum dot in an electrical field is studied taking into account the nonlocal coupling between the field of the light and the polarizability of the semiconductor. These nonlocal…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 F. Thiele , Ch. Fuchs , R. v. Baltz

In two-dimensional (2D) electron systems, an off-resonant high-frequency circularly polarized electromagnetic field can induce the quasi-stationary bound electron states of repulsive scatterers. As a consequence, the resonant scattering of…

Mesoscale and Nanoscale Physics · Physics 2020-08-07 O. V. Kibis , M. V. Boev , V. M. Kovalev

This work presents further analysis of the three- and four-neutron systems in the low energy regime using adiabatic hyperspherical methods. In our previous Phys. Rev. Lett. article (Phys. Rev. Lett. 125, 052501 (2020)), the low-energy…

Nuclear Theory · Physics 2021-03-03 Michael D. Higgins , Chris H. Greene , Alejandro Kievsky , Michele Viviani

Shifts from the expected nuclear magnetic resonance frequencies of antimony and bismuth donors in silicon of greater than a megahertz are observed in electrically detected magnetic resonance spectra. Defects created by ion implantation of…

The 2-10 keV continuum of AGN is generally well represented by a single power law. However, at smaller energies the continuum displays an excess with respect to the extrapolation of this power law, called the ''soft X-ray excess''. Until…

We propose and analyze an efficient scheme for suppressing the absorption of a weak probe field based on intersubband transitions in a four-level asymmetric coupled-quantum well (CQW) driven coherently by a probe laser field and a control…

Optics · Physics 2008-03-14 Wen-Xing Yang , Jin Xu , Ray-Kuang Lee

Natural and artificial light harvesting systems often operate in a regime where the flux of photons is relatively low. Besides absorbing as many photons as possible it is therefore paramount to prevent excitons from annihilation via photon…

Quantum Physics · Physics 2017-10-24 K. D. B. Higgins , B. W. Lovett , E. M. Gauger

Armed with a new solution to the four-body problem, we reanalyze the recent Innsbruck observation of an Efimov resonance in three-body collisions of cesium atoms, and show that it provides evidence of new, universal four-body physics as…

Atomic Physics · Physics 2009-06-02 Javier von Stecher , Jose P. D'Incao , Chris H. Greene