Description of superdeformed bands in light N=Z nuclei using the cranked HFB method

Superdeformed states in light $N=Z$ nuclei are studied by means of the self-consistent cranking calculation (i.e., the P + QQ model based on the cranked Hartree-Fock-Bogoliubov method). Analyses are given for two typical cases of superdeformed bands in the $A \simeq 40$ mass region, that is, bands where backbending is absent ($^{40}$Ca) and present ($^{36}$Ar). Investigations are carried out, particularly for the following points: cross-shell excitations in the sd and pf shells; the role of the g$_{9/2}$ and d$_{5/2}$ orbitals; the effect of the nuclear pairing; and the interplay between triaxiality and band termination.Comment: 17 pages, 18 figures, accepted in Phys. Rev.

Ancilla-Driven Universal Quantum Computation

We propose a method of manipulating a quantum register remotely with the help of a single ancilla that steers the evolution of the register. The fully controlled ancilla qubit is coupled to the computational register solely via a fixed unitary two-qubit interaction, E, and then measured in suitable bases. We characterize all interactions E that induce a unitary, step-wise deterministic measurement back-action on the register sufficient to implement any arbitrary quantum channel. Our scheme offers significant experimental advantages for implementing computations, preparing states and performing generalized measurements as no direct control of the register is required.Comment: 4 pages, 3 figure

A comparative study of managerial stress in greater China : the direct and indirect effects of coping strategies and work locus of control

The present study aims at comparing the direct and indirect effects of coping strategies (control and support coping) and work locus of control (externality) on the stress-strain relationships among managers in Greater China (Peopled Republic of China [PRC], Hong Kong, and Taiwan) using the Occupational Stress Indicator (OSI). Self-administered survey method was employed to collect data from 249 (164 males, 85 females) managers in China, 280 (159 males, 120 females, 1 unclassified) managers in Hong Kong, and 347 (191 males, 151 females, 5 unclassified) managers in Taiwan. The direct and indirect effects of control coping, support coping, and locus of control on some stress-strain relationships were demonstrated in the studied samples. The similarities and differences in managerial stress in Greater China were discussed according to economic and socio-cultural variations

Delocalization power of global unitary operations on quantum information

We investigate how originally localized two pieces of quantum information represented by a tensor product of two unknown qudit states are delocalized by performing two-qudit global unitary operations. To characterize the delocalization power of global unitary operations on quantum information, we analyze the necessary and sufficient condition to deterministically relocalize one of the two pieces of quantum information to its original Hilbert space by using only LOCC. We prove that this LOCC one-piece relocalization is possible if and only if the global unitary operation is local unitary equivalent to a controlled-unitary operation. The delocalization power and the entangling power characterize different non-local properties of global unitary operations.Comment: 14 pages, 1 figur

Operational approach to the Uhlmann holonomy

We suggest a physical interpretation of the Uhlmann amplitude of a density operator. Given this interpretation we propose an operational approach to obtain the Uhlmann condition for parallelity. This allows us to realize parallel transport along a sequence of density operators by an iterative preparation procedure. At the final step the resulting Uhlmann holonomy can be determined via interferometric measurements.Comment: Added material, references, and journal reference

Nest visitors of Vespula wasps and their potential use for biological control in an invaded range

The common and the German wasp, Vespula vulgaris and V. germanica, have proved to be prolific invasive species capable of degrading local ecosystems and costing invaded countries millions of dollars annually. Despite clear incentive, control strategies are yet to have any significant deleterious impact on invasive populations. Several species of arthropods are known to inhabit Vespula nests and feed upon developing larvae as either parasitoids or predators. Recent control strategies propose the use of such parasitoids as agents of biocontrol against invasive wasps (Volucella inanis in particular). Despite a general understanding of parasitoid ecology, some aspects such as prevalence, distribution, and behaviour remain limited. Here, we surveyed natural enemy prevalence in wasp nests over the period of three years and we tested larvae prey preference of two Volucella species, V. inanis and V. zonaria towards Vespula wasps. We find V. inanis to be the most prevalent of four prominent candidates for Vespid biocontrol—V. inanis, V. zonaria, Sphecophaga vesparum, and Metoecus paradoxus. Using two-choice assays, we find larvae of V. inanis to have slight yet significant prey preference for V. vulgaris larvae over V. germanica larvae, whilst V. zonaria display no preference. Furthermore, V. inanis were not averse to still predating upon V. germanica, doing so in 41% of trials. Prior exposure has no effect on the prey-preference. Our work provides experimental evidence that V. inanis is a promising candidate for biocontrol of invasive Vespula wasps, as the larvae predate on both target species of Vespula and display no exclusive preference among them

Age differences in work adjustment : a study of male and female managerial stress, coping strategies and locus of control in Hong Kong

The present study is a 15 month project which involved data collection from Hong Kong managers at three points to examine mechanisms by which age would relate to work well-being. A total of 634 managers, both male and female, was drawn by random sampling and purposive sampling methods. The results showed that age was negatively related to job strains and quitting intention, and positively related to job satisfaction. Furthermore, older managers reported fewer sources of stress, better control coping, and a more internal work locus of control. Multiple regression analyses suggested that relations of age with job satisfaction and well-being can be attributed to the better coping, greater internality, lower sources of stress, higher organizational level, and longer tenure of older managers, although differences occurred as a function of gender and the specific well-being measure

Direct estimations of linear and non-linear functionals of a quantum state

We present a simple quantum network, based on the controlled-SWAP gate, that can extract certain properties of quantum states without recourse to quantum tomography. It can be used used as a basic building block for direct quantum estimations of both linear and non-linear functionals of any density operator. The network has many potential applications ranging from purity tests and eigenvalue estimations to direct characterization of some properties of quantum channels. Experimental realizations of the proposed network are within the reach of quantum technology that is currently being developed.Comment: This paper supersedes the paper quant-ph/0112073, titled "Universal Quantum Estimator". We emphasise the estimation of linear and non-linear functionals of a quantum stat

Identifying an Experimental Two-State Hamiltonian to Arbitrary Accuracy

Precision control of a quantum system requires accurate determination of the effective system Hamiltonian. We develop a method for estimating the Hamiltonian parameters for some unknown two-state system and providing uncertainty bounds on these parameters. This method requires only one measurement basis and the ability to initialise the system in some arbitrary state which is not an eigenstate of the Hamiltonian in question. The scaling of the uncertainty is studied for large numbers of measurements and found to be proportional to one on the square-root of the number of measurements.Comment: Minor corrections, Accepted for publication in Physical Review