FLASH—A superluminal communicator based upon a new kind of quantum measurement

The FLASH communicator consists of an apparatus which can distinguish between plane unpolarized (PUP) and circularly unpolarized (CUP) light plus a simple EPR arrangement. FLASH exploits the peculiar properties of measurements of the Third Kind. One purpose of this article is to focus attention on the operation of idealized laser gain tubes at the one-photon limit.FLASH: acronym for First Laser-Amplified Superluminal Hookup.     

Identity method—a new tool for studying chemical fluctuations

Event-by-event fluctuations of the chemical composition of the hadronic system produced in nuclear collisions are believed to be sensitive to properties of the transition between confined and deconfined strongly interacting matter. In this paper a new technique for the study of chemical fluctuation, the identity method, is introduced and its features are discussed. The method is tested using data on central PbPb collisions at 40 A GeV registered by the NA49 experiment at the CERN SPS.     

Esca microscope — a new approach for imaging in XPS

This work demonstrates the feasibility of a novel yet simple method of obtaining XPS images using a conventional X-ray photoelectron spectrometer with a minimum of modification. A spherical sector electron energy analyser is operated in the selected area mode (small input aperture, moderate lens magnification) and deflection plates are introduced between the input lens and the sample, allowing the virtual image of the input aperture to be raster-scanned across the sample surface. The image is then formed by using the customary spectrometer output to z-modulate a synchronously raster-scanned video monitor. At present, the resolution is 150 μ but improvements to 10 μ should eventually be possible. Examples are given of studies on electronic components with insulating and conducting areas.     

The τ lepton as a laboratory for quantum chromodynamics

Decays of the τ lepton provide a clean environment to study hadron dynamics in an energy regime dominated by resonances. Inclusive spectral functions are the basis for quantum chromodynamics (QCD) analyses, providing a most accurate determination of the strong coupling constant and quantitative information on nonperturbative contributions. The τ vector spectral function is used together with e⁺e⁻ data in order to compute vacuum polarization integrals arising in the calculations of the anomalous magnetic moment of the muon and the running of the electromagnetic coupling constant. To cite this article: M. Davier, A. Höcker, C. R. Physique 3 (2002) 1223–1233.     

How good must single photon sources and detectors be for efficient linear optical quantum computation?

We present a scheme for linear optical quantum computation that is highly robust to imperfect single photon sources and inefficient detectors. In particular we show that if the product of the detector efficiency with the source efficiency is greater than 2/3, then efficient linear optical quantum computation is possible. This high threshold is achieved within the cluster state paradigm for quantum computation.     

Coherent states for a quantum particle on a Möbius strip

The coherent states for a quantum particle on a Möbius strip are constructed and the relation with the natural phase space for fermionic fields is shown. The explicit comparison of the obtained states with previous works where the cylinder quantization was used and the spin 1/2 was introduced by hand is given.     

Mixed-ligand Al complex—a new approach for more high efficient OLEDs

The mixed-ligand Aluminum bis(8-hydroxyquinoline) acetylacetonate (Alq₂Acac) complex was presented and its performance as electroluminescent and electron transporting layer for OLED was studied. The photophysical properties of the novel complex were investigated and compared with the properties of the parent Alq₃. Highly efficient OLED based on the mixed-ligand Al complex was developed with two times higher luminescence and efficiency compared to the identical OLED based on the conventional Alq₃ The better performance of the devices make the novel Al complex a very promising material for OLEDs.     

Announcing a new journal——PHOTONICS Research

Editor-in-Chief:Prof.Zhiping(James)Zhou,Peking University Photonics Research(PR)is an English-language,peer-reviewed open access journal serving as an international platform for optics researchers to share theoretical and applied research progress in optics and photonics.PR is co-published by Chinese Laser Press(CLP)and OSA.The scope of PR includes the following topics:     

Excitons in quantum—dot quantum—well nanoparticles

A variational calculation is presented for the ground-state properties of excitons confined in spherical core-shell quantum-dot quantum-well (QDQW) nanoparticles. The relationship between the exciton states and structure parameters of QDQW nanoparticles is investigated, in which both the heavy-hole and the light-hole exciton states are considered. The results show that the confinement energies of the electron and hole states and the exciton binding energies depend sensitively on the well width and core radius of the QDQW structure. A detailed comparison between the heavy-hole and light-hole exciton states is given. Excellent agreement is found between experimental results and our calculated 1s_e－1s_h transition energies.     

A new non-perturbative approach in quantum mechanics for time-independent Schr?dinger equations

A new non-perturbative approach is proposed to solve time-independent Schr?dinger equations in quantum mechanics.It is based on the homotopy analysis method(HAM)that was developed by the author in 1992 for highly nonlinear equations and has been widely applied in many fields.Unlike perturbative methods,this HAM-based approach has nothing to do with small/large physical parameters.Besides,convergent series solution can be obtained even if the disturbance is far from the known status.A nonlinear harmonic oscillator is used as an example to illustrate the validity of this approach for disturbances that might be one thousand times larger than the possible superior limit of the perturbative approach.This HAM-based approach could provide us rigorous theoretical results in quantum mechanics,which can be directly compared with experimental data.Obviously,this is of great benefit not only for improving the accuracy of experimental measurements but also for validating physical theories.     

Holonomic quantum computation based on the scalar Aharonov–Bohm effect for neutral particles and linear topological defects

We discuss holonomic quantum computation based on the scalar Aharonov–Bohm effect for a neutral particle. We show that the interaction between the magnetic dipole moment and external fields yields a non-abelian quantum phase allowing us to make any arbitrary rotation on a one-qubit. Moreover, we show that the interaction between the magnetic dipole moment and a magnetic field in the presence of a topological defect yields an analogue effect of the scalar Aharonov–Bohm effect for a neutral particle, and a new way of building one-qubit quantum gates.     

A new quantum group associated with a ‘nonstandard’ braid group representation

A new quantum group is derived from a nonstandard braid group representation by employing the Faddeev-Reshetikhin-Takhtajan constructive method. The classical limit is not a Lie superalgebra, despite relations like x ²–y ²=0. We classify all finite-dimensional irreducible representations of the new Hopf algebra and find only one- and two-dimensional ones.     

Editorial: Hybrid quantum systems – new perspectives on quantum state control

We give a brief sketch of the emerging field of quantum mechanical hybrid systems through a cross section of research papers on topics of current interest contained in this Topical Issue.     

Exergy of nuclear radiation — a quantum statistical thermodynamics approach

The exergy of nuclear radiation is evaluated by using a simple quantum statistical thermodynamic approach. Only radiation particles with non-zero rest mass are considered (i.e. protons, neutrons, alpha and beta particles). The exergy and the exergy flux involve efficiency-like factors affecting the internal energy and the energy flux, respectively. These factors are generally different from both the usual Carnot factor and the Petela-Landsberg-Press factor that appears in the exergy of blackbody radiation. The efficiency-like factors are higher in the case of charged rather than neutral particles and in the case of enclosed rather than free radiation. The results are compared with those obtained previously by using a classical thermodynamic theory.      

Determining the efficacy of a nanotechnology media product in enhancing children’s engagement with nanotechnology

Public engagement in nanotechnology media products can lead to a greater interest in understanding of nanotechnology. A study was undertaken to determine middle school student engagement in Nanooze, a magazine featuring nanotechnology research that has been developed for a young adult audience. Teachers at 116 Detroit middle schools distributed two issues of the magazine to their students, and surveys were collected from 870 students after reading the magazines. Results suggest that the majority of students liked reading the magazine and learned something about nanotechnology. Engagement in nanotechnology led to understanding of nanotechnology. The Nanooze magazine was an effective medium for engaging middle school students in learning about nanotechnology.     

OASIS4.0—a new version of the program OASIS for phasing protein diffraction data

<正>The program OASIS4.0 has been released.Apart from the improved single-wavelength anomalous diffraction (SAD) phasing algorithm described in a separate paper,an important new feature in this version is the automation of the iterative phasing and model-building process in solving protein structures.A new graphical user's interface(GUI) is provided for controlling and real-time monitoring the dual-space iterative process.The GUI is discussed in detail in the present paper.     

The relativistic bound states for a new ring-shaped harmonic oscillator

In this paper a new ring-shaped harmonic oscillator for spin 1/2 particles is studied, and the corresponding eigenfunctions and eigenenergies are obtained by solving the Dirac equation with equal mixture of vector and scalar potentials. Several particular cases such as the ring-shaped non-spherical harmonic oscillator, the ring-shaped harmonic oscillator, non-spherical harmonic oscillator, and spherical harmonic oscillator are also discussed.     

Melting a Hubbard dimer: benchmarks of ‘ALDA’ for quantum thermodynamics

The competition between evolution time, interaction strength, and temperature challenges our understanding of many-body quantum systems out-of-equilibrium. Here, we consider a benchmark system, the Hubbard dimer, which allows us to explore all the relevant regimes and calculate exactly the related average quantum work. At difference with previous studies, we focus on the effect of increasing temperature, and show how this can turn the competition between many-body interactions and driving field into synergy. We then turn to use recently proposed protocols inspired by density functional theory to explore if these effects could be reproduced by using simple approximations. We find that, up to and including intermediate temperatures, a method which borrows from ground-state adiabatic local density approximation improves dramatically the estimate for the average quantum work, including, in the adiabatic regime, when correlations are strong. However at high temperature and at least when based on the pseudo-LDA, this method fails to capture the counterintuitive qualitative dependence of the quantum work with interaction strength, albeit getting the quantitative estimates relatively close to the exact results.     

Novel multi-band quantum soliton states for a derivative nonlinear Schrödinger model

We show that localized N-body soliton states exist for a quantum integrable derivative nonlinear Schrödinger model for several nonoverlapping ranges (called bands) of the coupling constant η. The number of such distinct bands is given by Euler's φ-function which appears in the context of number theory. The ranges of η within each band can also be determined completely using concepts from number theory such as Farey sequences and continued fractions. We observe that N-body soliton states appearing within each band can have both positive and negative momentum. Moreover, for all bands lying in the region η>0, soliton states with positive momentum have positive binding energy (called bound states), while the states with negative momentum have negative binding energy (anti-bound states).