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Atomtronics: Coherent Control of Atomic Flow via Adiabatic Passage
Published in Xavier Oriols, Jordi Mompart, Applied Bohmian Mechanics, 2019
Albert Benseny, Joan Bagudà, Xavier Oriols, Gerhard Birkl, Jordi Mompart
In this section we will design a single-hole diode by using the collisional interaction between two bosons as a control parameter to allow the hole transport from left to right, and inhibit the transport from right to left (see Fig. 3.12a). Thus, Fig. 3.13a shows the fidelity of the bosonic hole transport processes FL→RB,FR→LB, and FR→MB against the strength of the s-wave-scattering length, that can be tuned by adjusting a Feshbach resonance [49]. The parameter values for the temporal variation of the traps are taken as in Fig. 3.2 such that the fidelity of the hole transport process from left to right, FL→RB (circles in Fig. 3.13a), is larger than 0.99 above a certain threshold value for the scattering length, indicated by point A in Fig. 3.13a, i.e., when the interaction is strong enough and the bosons become hardcore.
Matter wave solitons and other localized excitations in Bose–Einstein condensates in atom optics
Published in Kuppuswamy Porsezian, Ramanathan Ganapathy, Odyssey of Light in Nonlinear Optical Fibers, 2017
P. Muruganandam, M. Lakshmanan
The experimental realization of BECs in dilute alkali-metal gases confined in magnetic traps has triggered an immense interest in studying the properties of ultra cold gases [11, 12]. In particular, several attempts have been made by many experimenters worldwide to understand the properties of ultra cold matter and to exploit it for various purposes such as atom laser, atom interferometry, simulation of condensed-matter problems, quantum computing, information processing, and so on. An interesting dynamical feature is the formation of bright and dark matter wave solitons [13–26]. Matter-wave soli-tons in atom optics are expected to be useful for applications in atom lasers including atom interferometry, coherent atom transport, and so on [27]. The behavior of a BEC crucially depends on the sign of the atomic interactions: dark (bright) solitons can be created in BECs with repulsive (attractive) interactions, resulting from the positive (negative) scattering length. The sign of the s-wave atomic scattering length changes by applying Feshbach resonance [28–30].
Hydrogen molecule as seen in electron and positron scattering
Published in Molecular Physics, 2022
G. P. Karwasz, M. Karawacki, F. Carelli, K. Fedus
Similar to that by Kolos and Wolniewicz, progress was triggered sixty years ago in the experimental electron-atom and molecule scattering. Schulz [6] discovered a vibrational structure in the total cross-section (TCS) in N, testifying a temporal capture of the incoming electron by the N molecules (now referred to as a ‘shape of the potential’ resonance [7]). In the differential elastic cross section (under 72 scattering angle) in helium, Schulz observed [8] a narrow structure slightly below the threshold for the electronic excitation (now classified as a Feshbach resonance). But as we show in a picture redrawn from the magnum opus by Mott and Massey [9], in 1962, the agreement between the theory and experiment, as seen in electron scattering on H was roughly qualitative, see Figure 1.
Vector vortex solitons in two-component Bose–Einstein condensates with modulated nonlinearities and a harmonic trap
Published in Journal of Modern Optics, 2018
Si-Liu Xu, Ze-Qiang Wang, Jun-Rong He, Li Xue, Milivoj R. Belić
BEC dynamics at ultra-low temperatures in the mean-field approximation are accurately described by the Gross–Pitaevskii equation (GPE), which has been examined in different configurations; of interest here will be the case of spatially varying nonlinearity coefficients (10), which can be realized experimentally by suitably tuning the s-wave scattering length in space or by employing external magnetic (11) or optical (12) fields close to the Feshbach resonance (FR).
Theoretical investigations of structural, spectroscopic and electron collision data of acetone
Published in Molecular Physics, 2021
D. Prajapati, P. C. Vinodkumar, C. Limbachiya, M. Vinodkumar
Figure 3 shows eigenphase sum for e-acetone in point group symmetry, which provides an important diagnostic of scattering calculation. Here we present eigenphase curve for symmetry states and from the sum of eigenvalues of K-matrix for CAS-CI model. These were further analysed to obtain the position and width of resonances by performing Breit–Wigner fits to the eigenphase diagram through the program module RESON [44]. Table 6 indicates total 20 resonances corresponding to , , , and , which can be further classified as Electronic Excited Feshbach Resonance (EEFR) and Shape Resonance (SR). Tables 4 and 5 provide the transition details for resonance and width parameter. For symmetry, we have predicted one EEFR at 7.63 eV with the width of 0.020 eV and four EEFR at 5.84 eV, 8.26 eV, 8.87 eV, 9.22 eV and 9.51 eV of width 0.155 eV, 0.110 eV, 0.030 eV, 0.050 eV and 0.040 eV respectively. Pastega et al. [22] and Homem et al. [21] found resonance around 8.0 and 10.0 respectively. For symmetry, we found the low lying resonance at 0.50 eV, shape resonance at 2.56 eV and three EEFR at 5.66 eV, 9.33 eV and 9.83 eV in comparison with 8.0 eV resonance of Homem et al. [21]. Present study confirmed the finding of Homem et al. [21] and Pastega et al. [22] that a feature of e-acetone scattering is the existence of a shape resonance at 2.6 eV for symmetry component. As symmetry component belongs to resonances, we found two EEFR at 5.66 eV and 5.70 eV and two SR at 6.28 eV and 8.21 eV in comparison with 8.0 eV resonance from Homem et al. [21].