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The de Broglie Wave Nature of Molecules, Clusters and Nanoparticles
Published in Klaus D. Sattler, st Century Nanoscience – A Handbook, 2019
Stefan Gerlich, Stefan Kuhn, Armin Shayeghi, Markus Arndt
Atom interferometry started a few decades later, with the development of nanomechanical diffraction masks and intense narrowband laser light. It has gone a long way from first demonstrations of coherent atom beam splitters [11,12] to full-fledged interferometers [13-15] that can nowadays even delocalize every single atom on the half-meter scale [16]. Such large-scale instruments are being used for advanced tests of general relativity. Smaller and yet precise versions are being developed and commercialized as mobile platforms for inertial sensing and navigation [6,17]. The combination of many atoms into an ultracold quantum degenerate ensemble at nanokelvin temperatures, a Bose-Einstein condensate (BEC) [7,18,19], shows atomic coherence over mesoscopic scales. Such novel quantum states of matter find applications in matter-wave interferometry and in condensed-matter quantum simulations [20].
The semiclassical theory
Published in M. G. Benedict, A. M. Ermolaev, V. A. Malyshev, I. V. Sokolov, E. D. Trifonov, Super-radiance, 2018
M. G. Benedict, A. M. Ermolaev, V. A. Malyshev, I. V. Sokolov, E. D. Trifonov
We are going to discuss below spontaneous cooperative Raman scattering (CRS) which is different from the stimulated effect and also different from the so-called CARS (coherent anti-Stokes’ Raman scattering) where an additional incident field at the scattering frequency is injected into the sample [15]. In spontaneous CRS we have only one incident field, but the atomic dipoles that oscillate at the scattering frequency, retain their phase memory and therefore they radiate cooperatively. This can be realized if the excitation and the scattering processes are fast enough to prevent phase relaxation destroying atomic coherence. If a level population is changed significantly during the interaction, then the intensity of Raman scattering can be proportional to the square of the number of the scattering centres, N2, which is the characteristic feature of all super-radiant effects.
Soliton signals propagating in fiber waveguides and slow light generation
Published in Iraj Sadegh Amiri, Abdolkarim Afroozeh, Harith Ahmad, Integrated Micro-Ring Photonics, 2016
Iraj Sadegh Amiri, Abdolkarim Afroozeh, Harith Ahmad
In 2002, Longhi et al. predicted the great advantages obtained from the light signals speed control within an optical fiber. They demonstrated superluminal optical pulse propagation through fiber Bragg gratings (FBGs) for communication optical systems, (Longhi et al., 2002). Stenner et al. used fast light medium that exploits the spectral region of anomalous dispersion between two closely spaced amplifying resonances realized by creating large atomic coherence in a laser driven potassium vapour. He obtained larger pulse advancement for a smooth Gaussian shaped pulse. Thevenaz et al. achieved both time advancement and delay in optical fibers using stimulated Brillouin scattering in 2007 (Thévenaz et al., 2007). In 2006, Mok et al. obtained considerable delays by launching powerful optical pulses at the edge of the rejection band of the FBG in transmission. The Kerr effect was used to modify the delay via a shift of the FBG (Mok et al., 2006).
Nonlinear optical response properties of a quantum dot embedded in a semiconductor microcavity: possible applications in quantum communication platforms
Published in Journal of Modern Optics, 2021
Vijay Bhatt, Sabur A. Barbhuiya, Pradip K. Jha, Aranya B. Bhattacherjee
Using Equation (19), we plot the real and imaginary part of in Figure 6. The real part ) is the absorption while the imaginary part Im() is the dispersive behaviour. Figure 6(a,b) describes the absorption and dispersive behaviour when the exciton is not coupled with the mechanical mode (). The dispersion curve demonstrates an anomalous behaviour around (near the resonant electronic transition). When the slightly greater radiation frequency interact with refractive index makes it lesser than unity and with increasing the frequency refractive index decreases, this leads to Anomalous dispersion effect. The theory of Anomalous dispersion developed by Lord Rayleigh and demonstrated this phenomenon for a mechanical oscillator [68,69]. Recently, in atomic systems, electromagnetic interaction due to atomic coherence in degenerate two-level systems leads to negative dispersion at the resonant frequency for an atomic transition. In the anomalous dispersion region, the group velocity of light can be negative [70].
Transformation of twin-peak electromagnetically induced transparency to twin-peak electromagnetically induced absorption based on magnetic dipole and dielectric resonator
Published in Waves in Random and Complex Media, 2023
Yu-jing Yin, You Lv, Didi Zhu, Hai-Feng Zhang
Electromagnetically induced absorption (EIA), an enhancement of the absorption resulting from atomic coherence induced by optical radiation, serves as the complementary phenomenon of EIT. EIA is first studied by Lezama et al. In 1998, [18] the theoretical condition for implementing EIA was given in that work. Additionally, Taubert et al. [19] first experimentally investigated EIA with plasmonic resonators, recognizing that altering the phase might boost the absorption effect. In the same year, a radiating dual-oscillator model was introduced by Tassin et al. [20] to depict both the absorption and the scattering properties, revealing that the transition from EIT to EIA is accomplished via increasing the dissipative loss of the dark resonator and decreasing the coupling strength. The radiation-broadened resonators are applied in his work to make up for the impossibility of reaching the phase difference in truly homogenized metastructure (MS) to achieve EIA. Besides, phase-shift modulations have been proven a wonderful approach to transforming EIT into EIA. A triple-resonator was put forward by Zhang et al., [21] the change of the difference of phase at the resonance frequency between the surface currents of three resonators leading to the shift from EIT to EIA with its near-field absorption caused by a strong magnetic response. Although research on EIA is not rare, too, few people pay attention to the auto transformation from EIT to EIA, which requires our attention. In this paper, vanadium dioxide (VO2) is employed to promote the switch between twin-peak EIT and twin-peak EIA.
Generation of quintupartite entanglement with an atom-assisted dual-cavity optomechanical system
Published in Journal of Modern Optics, 2021
Xihua Yang, Pingping Wang, Mingfei Cheng, Zhiyong Yin
We have shown that the quadripartite entanglement among the two cavity fields, two mechanical oscillators, and microscopic atoms can be realized via atomic coherence and cavity field radiation pressure in the atom-assisted dual-cavity optomechanical hybrid system. This hybrid system provides an effective and convenient platform for testing the entangled feature between macroscopic (mechanical oscillators) and microscopic (atoms, photons) matters, between macroscopic and macroscopic matters, as well as between microscopic and microscopic matters, which opens the way to realistic applications in various quantum information protocols.