Dynamical effects of QCD in q2qˉ2q^2 \bar{q}^{2} systems

We study the coupling of a tetraquark system to an exchanged meson-meson channel, using a pure gluonic theory based four-quark potential {\em matrix} model which is known to fit well a large number of data points for lattice simulations of different geometries of a four-quark system. We find that if this minimal-area-based potential matrix replaces the earlier used simple Gaussian form for the gluon field overlap factor $f$ in its off-diagonal terms, the resulting $T$-matrix and phase shifts develop an angle dependence whose partial wave analysis reveals $D$ wave and higher angular momentum components in it. In addition to the obvious implications of this result for the meson-meson scattering, this new feature indicates the possibility of orbital excitations influencing properties of meson-meson molecules through a polarization potential. We have used a formalism of the resonating group method, treated kinetic energy and overlap matrices on model of the potential matrix, but decoupled the resulting complicated integral equations through the Born approximation. In this exploratory study we have used a quadratic confinement and not included the spin-dependence; we also used the approximation of equal constituent quark masses.Comment: 18 pages, 9 figure

Exact Diagonalization Study of Bose-Condensed Gas with Finite-Range Gaussian Interaction

We investigate a system of $N$ spinless bosons confined in quasi-two-dimensional harmonic trap with repulsive two-body finite-range Gaussian interaction potential of large $s$-wave scattering length. Exact diagonalization of the Hamiltonian matrix is carried out to obtain the $N$-body ground state as well as low-lying excited states, using Davidson algorithm in beyond lowest-Landau-level approximation. We examine the finite-range effects of the interaction potential on the many-body ground state energy as also the degree of condensation of the Bose-condensed gas. The results obtained indicate that the finite-range Gaussian interaction potential enhances the degree of condensation compared to the zero-range interaction potential. We further analyze the effect of finite-range interaction potential on the breathing mode collective excitation. Our theoretical results may be relevant for experiments currently conducted on quasi-two-dimensional Bose gas with more realistic interaction potential.Comment: 4 pages,3 figures, RevTe

Two-photon entanglement in multi-qubit bi-directional waveguide QED

We study entanglement generation and control in bi-directional waveguide QED driven by a two photon Gaussian wavepacket. In particular, we focus on how increasing the number of qubits affects the overall average pairwise entanglement in the system. We also investigate how the presence of a second photon can introduce non-linearities, thereby manipulating the generated entanglement. In addition, we show that through the introduction of chirality and small decay rates, entanglement can be stored and enhanced up to factors of 2 and 3, respectively. Finally, we analyze the influence of finite detunnings and time-delays on the generated entanglement.Comment: 13 pages, 7 figure

‘ĀʼIsha Bint Al-Shāṭi's Thoughts on Tarāduf and Their Implications for the Istinbāṭ of Law

As a book containing miracles, in literature, the miracles of the Quran have been proven by ʻĀʼisha Bint al-Shāṭiʼ through her theory i‘jāz lughawī. She showed the importance of the correct method of interpretation of the Qurʼan from aspects of tarāduf (synonym). However, despite following the rule of "there is no word that has the same meaning (tarāduf) in the Quran" as commonly known in the theory of iʻjāz al-qur'ān (the inimitability of the Qurʼān), her thoughts on tarāduf and their implications for the istinbāṭ (inference) of Islamic law are still unclear. Hence, this article discusses the relation and influence of ʻĀʼisha Bint al-Shāṭiʼs thoughts related to verses of laws. By studying the book of al-I'jāz al-Bayānī lil Qur`ān wa Masā'il Ibn al-Azraq and other relevance sources, this article concludes that ʻĀʼisha Bint al-Shāṭiʼs thoughts related to verses of law are still abstract and difficult to be applied, hence it does not give a significant influence on the strengthening of Islamic legal propositions

Influence of Disorder on Electromagnetically Induced Transparency in Chiral Waveguide Quantum Electrodynamics

We study single photon transport in a one-dimensional disordered lattice of three-level atoms coupled to an optical waveguide. In particular, we study atoms of \Lambda-type that are capable of exhibiting electromagnetically induced transparency (EIT) and separately consider disorder in the atomic positions and transition frequencies. We mainly address the question of how preferential emission into waveguide modes (chirality) can influence the formation of spatially localized states. Our work has relevance to experimental studies of cold atoms coupled to nanoscale waveguides and has possible applications to quantum communications

Controlling tripartite entanglement among optical cavities by reservoir engineering

We study how to control the dynamics of tripartite entanglement among optical cavities using non-Markovian baths. In particular, we demonstrate how the reservoir engineering through the utilization of non-Markovian baths with different types of Lorentzian and ohmic spectral densities can lead to an entanglement survival for longer times and in some cases considerable regain of seemingly lost entanglement. Both of these behaviors indicate a better sustainability of entanglement (in time) compared to the usual Markovian bath situations which assumes a flat spectrum of the bath around the system resonant frequency. Our scheme shows these effects in the context of optical cavities starting off in a maximally entangled W and Greenberger-Horne-Zeilinger (GHZ) tripartite states. In Lorentzian cases we find that the far detuned double Lorentzian baths with small coupling strengths and for ohmic type baths super-ohmic environments with smaller cutoff frequencies are the best candidates for preserving entanglement among cavities for significant amount of time. A non-Markovian quantum jump approach is employed to understand the entanglement dynamics in these cases, especially to recognize the collapse and revival of the entanglement in both W and GHZ states