Enhanced multipartite quantum correlations by non-Gaussian operations

We study how conditional photon operations can affect multipartite quantum correlations, specifically nonlocality and entanglement, of the continuous variable GHZ states. We find that the violation of the Mermin-Klyshko inequality revealing the multipartite nonlocality can be made stronger with photon subtraction applied on each mode of the original GHZ states, particularly in a weak squeezing regime. Photon addition applied on local modes also turns out to enhance the degree of multipartite nonlocality in a broad range of parameters. We further investigate the effects of the photon operations on the degree of multipartite entanglement by looking into the Gaussian tangle, the fidelity of teleportation network, and the quadrature correlations. We find that photon subtraction applied on two modes enhances those entanglement characteristics in a practical squeezing regime while there is no improvement made by photon addition.Comment: 11 pages, 10 figures, to appear in Phys. Rev.

Enhancing quantum entanglement for continuous variables by a coherent superposition of photon subtraction and addition

We investigate how the entanglement properties of a two-mode state can be improved by performing a coherent superposition operation of photon subtraction and addition, proposed by Lee and Nha [Phys. Rev. A 82, 053812 (2010)], on each mode. We show that the degree of entanglement, the EPR-type correlation, and the performance of quantum teleportation can be all enhanced for the output state when the coherent operation is applied to a two-mode squeezed state. The effects of the coherent operation are more prominent than those of the mere photon subtraction and the addition particularly in the small squeezing regime, whereas the optimal operation becomes the photon subtraction in the large-squeezing regime.Comment: 6 pages, 6 figures, published versio

Dispersion of Vascular Plant in An-do, Korea

AbstractThe vascular plants observed in the area were composed of a total of 342 taxa; 104 families, 239 genus, 309 species, 30 varieties, 2 forms and 1 sub-species. The endangered species found in the area were Glehnia littoralis Fr. Schm. and Milletia japonica (Siebold & Zucc.) A.Gray. The five endemic plants were found growing in the area like Carpinus coreana Nakai., Celtis choseniana Nakai, Clematis trichotoma, Spiraea prunifolia for. simpliciflora and Weigela subsessilis L.H.Bailey. Specialized plants of Geumodo were a total of 45 species; 34 taxa in Grade I, 10 taxa in Grade III, and 1 taxon in Grade V. Glehnia littoralis Fr. Schm. and Milletia japonica (Siebold & Zucc.) A.Gray confirmed in this study formed a colony alongside the coast and mountain paths. Currently, the construction to build water supply and sewer systems destroyed part of the colony. Therefore, in the long-term perspective, the conservation plan such as comprehensive research and monitoring on the ecosystem shall be established to protect indeciduous plants in the warm temperate zone

Ultraviolet photodepletion spectroscopy of dibenzo-18-crown-6-ether complexes with alkali metal cations

Ultraviolet photodepletion spectra of dibenzo-18-crown-6-ether complexes with alkali metal cations (M+-DB18C6, M = Cs, Rb, K, Na, and Li) were obtained in the gas phase using electrospray ionization quadrupole ion-trap reflectron time-of-flight mass spectrometry. The spectra exhibited a few distinct absorption bands in the wavenumber region of 35450−37800 cm^(−1). The lowest-energy band was tentatively assigned to be the origin of the S_0-S_1 transition, and the second band to a vibronic transition arising from the “benzene breathing” mode in conjunction with symmetric or asymmetric stretching vibration of the bonds between the metal cation and the oxygen atoms in DB18C6. The red shifts of the origin bands were observed in the spectra as the size of the metal cation in M^+-DB18C6 increased from Li^+ to Cs^+. We suggested that these red shifts arose mainly from the decrease in the binding energies of larger-sized metal cations to DB18C6 at the electronic ground state. These size effects of the metal cations on the geometric and electronic structures, and the binding properties of the complexes at the S_0 and S_1 states were further elucidated by theoretical calculations using density functional and time-dependent density functional theories

EFFECT OF SEAT TUBE ANGLE ON THE WORK EFFICIENCY OF LOWER LIMB MUSCLES DURING CYCLING

The effect of seat tube angle (STA) on work efficiency at lower limb muscle was evaluated during a pedal rotation using inverse dynamic model. Since the target is not professional cyclist, the various seat tube angles of 78, 68, 58 and 48 degrees was investigated. Cycling simulation was performed at 250W and 60rpm. The works of individual muscle of lower limb and the total work was estimated. The result shows that the total work of single leg at seat tube angles of 78, 68, 58 and 48 degrees were 168.1(J), 167.9(J), 168.9(J) and 170.8(J) respectively. In conclusion, the exertion of lower limb for delivering same amount of work to the crank is the smallest at around 72 degree of seat tube angle which mean work efficiency of lower limb is the greates