Suppercontinuum Generation in InP Nano Inner Cladding Fibers

The InP nano inner cladding fiber is fabricated by the method of modified chemical vapor deposition. The thickness of the InP nano thin film is about 16 nm. A 20 dB supercontinuum over 100nm in the telecommunication band is generated by infecting 1550nm, 120fs, 50MHz repetition rate optical pulse into this kind of fiber. Moreover, the results indicate that the width of the supercontinuum spectra can be influenced by the fiber length and pump power. The longer fiber at higher pump power can produce broader supercontinuum spectrum.

Quantitative conditions for time evolution in terms of the von Neumann equation

The adiabatic theorem describes the time evolution of the pure state and gives an adiabatic approximate solution to the Schr ¨odinger equation by choosing a single eigenstate of the Hamiltonian as the initial state. In quantum systems, states are divided into pure states(unite vectors) and mixed states(density matrices, i.e., positive operators with trace one). Accordingly, mixed states have their own corresponding time evolution, which is described by the von Neumann equation. In this paper, we discuss the quantitative conditions for the time evolution of mixed states in terms of the von Neumann equation. First, we introduce the definitions for uniformly slowly evolving and δ-uniformly slowly evolving with respect to mixed states, then we present a necessary and sufficient condition for the Hamiltonian of the system to be uniformly slowly evolving and we obtain some upper bounds for the adiabatic approximate error. Lastly, we illustrate our results in an example.

Continuity of the robustness of contextuality of empirical models

Recently, the robustness of contextuality(RoC) of an empirical model was discussed in [Sci. China-Phys. Mech. Astron. 59,640303(2016)], many important properties of the RoC have been proved except for its boundedness and continuity. The aim of this paper is to find an upper bound for the RoC over all of empirical models and prove that the RoC is a continuous function on the set of all empirical models. Lastly, a relationship between the RoC and the extent of violating the noncontextual inequalities is established for an n-cycle contextual box. This relationship implies that the RoC can be used to quantify the contextuality of n-cycle boxes.

The robustness of contextuality and the contextuality cost of empirical models

In this paper, we introduce and discuss the robustness of contextuality(Ro C) R_C(e) and the contextuality cost C(e) of an empirical model e. The following properties of them are proved.(i) An empirical model e is contextual if and only if R_C(e) > 0;(ii) the Ro C function R_C is convex, lower semi-continuous and un-increasing under an affine mapping on the set E M of all empirical models;(iii) e is non-contextual if and only if C(e) = 0;(iv) e is contextual if and only if C(e) > 0;(v) e is strongly contextual if and only if C(e) = 1. Also, a relationship between RC(e) and C(e) is obtained. Lastly, the Ro C of three empirical models is computed and compared. Especially, the Ro C of the PR boxes is obtained and the supremum 0.5 is found for the Ro C of all no-signaling type(2, 2, 2) empirical models.

Concentrating partially entangledW-class states on nonlocal atoms using low-Q optical cavity and linear optical elements

Entanglement plays an important role in quantum information science, especially in quantum communications. Here we present an efficient entanglement concentration protocol(ECP) for nonlocal atom systems in the partially entangled W-class states, using the single-photon input-output process regarding low-Q cavity and linear optical elements. Compared with previously published ECPs for the concentration of non-maximally entangled atomic states, our protocol is much simpler and more efficient as it employs the Faraday rotation in cavity quantum electrodynamics(QED) and the parameter-splitting method. The Faraday rotation requires the cavity with low-Q factor and weak coupling to the atom, which makes the requirement for entanglement concentration much less stringent than the previous methods, and achievable with current cavity QED techniques. The parameter-splitting method resorts to linear-optical elements only. This ECP has high efficiency and fidelity in realistic experiments, and some imperfections during the experiment can be avoided efficiently with currently available techniques.

Gap induced mode evolution under the asymmetric structure in a plasmonic resonator system

The modulation of resonance features in microcavities is important to applications in nanophotonics.Based on the asymmetric whispering-gallery modes(WGMs)in a plasmonic resonator,we theoretically studied the mode evolution in an asymmetric WGM plasmonic system.Exploiting the gap or nano-scatter in the plasmonic ring cavity,the symmetry of the system will be broken and the standing wave in the cavity will be tunable.Based on this asymmetric structure,the output coupling rate between the two cavity modes can also be tuned.Moreover,the proposed method could further be applied for sensing and detecting the position of defects in a WGM system.

Frictionless Multi-field Coupling Contact Problem for a Thermoelectric Layer Loaded by Two Rigid Punches

In this paper,the thermo-electro-mechanical coupling contact problem of thermoelectric material with double punches is analyzed accurately.Using the Fourier cosine transform technique,the thermo-electro-elastic problem is transformed into three sets of singular integral equations,which are numerically solved by the Gauss–Chebyshev integral formula according to the unknown normal electric current density,normal energy flux and normal contact stress.For a rigid flat indenter,the results can be covered by the degradation results of two rigid flat indenters.The numerical results reveal the interaction between two punches and the effect of thermoelectric load on the indentation behaviors.The interaction between the two punches reduces the contact pressure at the inner edge of the indenter as the thermoelectric load increases while increasing the stress singularity at the outer edge.The change of punches’spacing makes the singularity of normal stress at the inner and outer edges asymmetric.The results provide an in-depth understanding of the multi-region contact damage mechanism of thermoelectric material.