Neighboring optimal feedback control of multi- input nonlinear dynamical systems using discontinuous control

Neighboring optimal feedback control of multi-input nonlinear dynamic system

Emergence of junction dynamics in a strongly interacting Bose mixture

We study the dynamics of a one-dimensional system composed of a bosonic background and one impurity in single- and double-well trapping geometries. In the limit of strong interactions, this system can be modeled by a spin chain where the exchange coefficients are determined by the geometry of the trap. We observe non-trivial dynamics when the repulsion between the impurity and the background is dominant. In this regime, the system exhibits oscillations that resemble the dynamics of a Josephson junction. Furthermore, the double-well geometry allows for an enhancement in the tunneling as compared to the single-well case.Comment: 20 pages, 9 figure

Dynamical realization of magnetic states in a strongly interacting Bose mixture

We describe the dynamical preparation of magnetic states in a strongly interacting two-component Bose gas in a harmonic trap. By mapping this system to an effective spin chain model, we obtain the dynamical spin densities and the fidelities for a few-body system. We show that the spatial profiles transit between ferromagnetic and antiferromagnetic states as the intraspecies interaction parameter is slowly increased.Comment: 6 pages, 7 figure

Comparing 1D-3C et 1D-1C nonlinear dynamic responses of deep and shallow japanese sites, considering various assumptions

International audienceIn this paper, we present the results obtained with the CyberQuake computation code for two Japanese sites selected from the KiK-net and PARI accelerometric networks, which were proposed within the PRENOLIN international benchmark. The deep Kushiro (KiK-net KSRH10) and the shallow Sendai (PARI) sites were chosen as they are very close to a 1D geometry (horizontal layers). During the PRENOLIN benchmark, various 1D-1C computing assumptions with vertical incident waves were considered. Here, we present further works comparing results of 1D-1C / 1D-3C nonlinear transient dynamic computations, considering effective-stress / total-stress approaches, as well as vertical / oblique incident input motions, in order to review the usual main assumptions in 1D nonlinear site effects analyses, depending on site conditions. For the selected shallow site, the 1D-1C analysis with vertical incidence seems to be a better option. No clear trend is found in this case with respect to preferring the effective-stress or the total-stress model. The effective-stress analysis provides however better results in terms of predicted time-history ground motions at the site. For the deep site, the new computations performed in this study confirm that 1D-3C effective-stress analysis do improve the predictions. However, the discrepancy between the predictions and the recordings is still remaining since PRENOLIN, and cannot be explained by the new assumptions tested in this study. For both sites, no significant effect is observed, when considering oblique incidence for propagating waves. Computations with vertical incidence lead sometimes to better results

Realizing time crystals in discrete quantum few-body systems

The exotic phenomenon of time translation symmetry breaking under periodic driving - the time crystal - has been shown to occur in many-body systems even in clean setups where disorder is absent. In this work, we propose the realization of time-crystals in few-body systems, both in the context of trapped cold atoms with strong interactions and of a circuit of superconducting qubits. We show how these two models can be treated in a fairly similar way by adopting an effective spin chain description, to which we apply a simple driving protocol. We focus on the response of the magnetization in the presence of imperfect pulses and interactions, and show how the results can be interpreted, in the cold atomic case, in the context of experiments with trapped bosons and fermions. Furthermore, we provide a set of realistic parameters for the implementation of the superconducting circuit.Comment: 6 pages, 4 figure

Bethe ansatz solution of the closed anisotropic supersymmetric U model with quantum supersymmetry

The nested algebraic Bethe ansatz is presented for the anisotropic supersymmetric $U$ model maintaining quantum supersymmetry. The Bethe ansatz equations of the model are obtained on a one-dimensional closed lattice and an expression for the energy is given.Comment: 7 pages (revtex), minor modifications. To appear in Mod. Phys. Lett.

Large Motion Assessment in Soils Under Dynamic Loading

This paper presents the mathematical formulation of the nonlinear multiphase dynamic model meant for porous media, obtained by applying the finite transformation assumption. This assumption is appropriate when large motions take place either during mass wasting processes, such as large slumps and earthflows, or during earthquake events when site liquefaction occurs and results for instance in large irrecoverable settlements or lateral spreads. The weak formulation and numerical implementation of the dynamic model uses the mesh-free h-p clouds method, which is based on the more general Partition of Unity Method. The mesh-free numerical methods seem indeed to be more appropriate for large transformation problems, where geometry may change in an important manner during simulation, as usual mesh constraints no longer exist. The numerical simulations of observed liquefaction-induced lateral spreads, performed with the proposed model are not presented in this paper

Self-consistent Green function approach for calculations of electronic structure in transition metals

We present an approach for self-consistent calculations of the many-body Green function in transition metals. The distinguishing feature of our approach is the use of the one-site approximation and the self-consistent quasiparticle wave function basis set, obtained from the solution of the Schrodinger equation with a nonlocal potential. We analyze several sets of skeleton diagrams as generating functionals for the Green function self-energy, including GW and fluctuating exchange sets. Their relative contribution to the electronic structure in 3d-metals was identified. Calculations for Fe and Ni revealed stronger energy dependence of the effective interaction and self-energy of the d-electrons near the Fermi level compared to s and p electron states. Reasonable agreement with experimental results is obtained