Let M be a concircularly fiat totally real minimal submanifold in CP4. The infimum Vm of the volume V （M） of M is obtained, also the necessary and sufficient conditions of ＂V（M）=Vm＂ is given.
In this paper, we consider a class of submanifolds with parallel mean curvacture vector fields. We obitain the suffitient conditions that the above submanifolds is of tatall umbilical and that its codimension is decre...In this paper, we consider a class of submanifolds with parallel mean curvacture vector fields. We obitain the suffitient conditions that the above submanifolds is of tatall umbilical and that its codimension is decrease.展开更多
By using dressing actions of the G(n1,n-1)1,1-system, the authors study geometric transformations for flat time-like n-submanifolds with flat, non-degenerate normal bundle in anti-de Sitter space H1(2n-1)(-1), where G...By using dressing actions of the G(n1,n-1)1,1-system, the authors study geometric transformations for flat time-like n-submanifolds with flat, non-degenerate normal bundle in anti-de Sitter space H1(2n-1)(-1), where G(n-1,n-1)1,1 = O(2n - 2, 2)/O(n - 1,1)×O(n-1, 1).展开更多
Novel highly nonlinear photonic crystal fibers(HN-PCFs) with flattened dispersion are proposed by omitting 19 air holes as the fiber core.The simulation results show that the high nonlinearity and the flattened disper...Novel highly nonlinear photonic crystal fibers(HN-PCFs) with flattened dispersion are proposed by omitting 19 air holes as the fiber core.The simulation results show that the high nonlinearity and the flattened dispersion can be achieved simultaneously by employing only two types of air holes in the cladding.To reduce the confinement loss,the modified designs are presented.The confinement loss is below 0.1 dB/km at 1.55 μm,when seven layers of air-hole rings are introduced to the cladding.After modifying,the dispersion can change from-0.5 ps/(nm.km) to+0.5 ps/(nm.km) in the range from 1.35 μm to 2.06 μm,and the effective mode area is as low as 2.27 μm 2 at 1.55 μm.展开更多
We study the Bell's inequality and multipartite entanglement generation for initially maximally entangled states of free Dirac field in a non inertial frame and asymptotically flat Robertson–Walker space-time.For...We study the Bell's inequality and multipartite entanglement generation for initially maximally entangled states of free Dirac field in a non inertial frame and asymptotically flat Robertson–Walker space-time.For two qubit case,we show that the Bell's inequality always is violated as measured by the accelerated observers which are in the causally connected regions.On the other hand,for those observers in the causally disconnected regions inequality is not violated for any values of acceleration.The generated three qubit state from two qubit state due to acceleration of one parties has a zero 3-tangle.For a three qubit state,the inequality violated for measurements done by both causally connected and disconnected observers.Initially GHZ state with non zero 3-tangle,in accelerated frame,transformed to a four qubit state with vanishing 4-tangle value.On the other hand,for a W-state with zero 3-tangle,in non inertial frame,transformed to a four qubit state with a non-zero 4-tangle acceleration dependent.In an expanding space-time with asymptotically flat regions,for an initially maximally entangled state,the maximum value of violation of Bell's inequality in the far past decreased in the far future due to cosmological particle creation.For some initially maximally entangled states,the generated four qubit state due to expansion of space-time,has non vanishing 4-tangle.展开更多
We propose the sub-picosecond chirped soliton pulse propagation in copcave-dispersion-flattened fibers （CDFF）. The effects of pulse characteristics and the fiber dispersion parameters on propagation characteristics ...We propose the sub-picosecond chirped soliton pulse propagation in copcave-dispersion-flattened fibers （CDFF）. The effects of pulse characteristics and the fiber dispersion parameters on propagation characteristics of the chirped soliton pulse are numerically investigated in the CDFF by the split-step Fourier method （SSFM）. The unchirped soliton pulse can stably propagate with unchanged pulse width in the CDFE The temporal full width at half maximum （FWHM） of the chirped soliton performs a damped oscillation with the increase of propagation distance. The period and amplitude of the oscillation increase with the increase of the chirp parameter ｜C｜. The effect of high-order dispersion （β3-β6） on soliton propagation characteristics can be neglected. The soliton pulse slightly broadens with the increase of propagation distance and still maintains soliton characteristics when the fiber loss （ATT） is further considered. The variation of root-meansquare （RMS） spectral width with propagation distance is opposite to that of the temporal width. The output spectrum of soliton has a single peak for the unchirped case, while has multi-peak for chirped case. The temporal width of the soliton obviously increases with the increase of the initial width, decreases with the increase of dispersion peakD0 of the fiber, and slightly increases with the decrease of dispersion coefficients k1 and k2 of the fiber.展开更多
基金Supported by the NSF of Education Department of Henan Province(20021100002)Supported by the NSF of Education Department of Henan Province(200510475038)
文摘Let M be a concircularly fiat totally real minimal submanifold in CP4. The infimum Vm of the volume V （M） of M is obtained, also the necessary and sufficient conditions of ＂V（M）=Vm＂ is given.
文摘In this paper, we consider a class of submanifolds with parallel mean curvacture vector fields. We obitain the suffitient conditions that the above submanifolds is of tatall umbilical and that its codimension is decrease.
基金Project supported supported by the 973 Project of the Ministry of Science and Technology of Chinathe National Natural Science Foundation of China (No. 10301030).
文摘By using dressing actions of the G(n1,n-1)1,1-system, the authors study geometric transformations for flat time-like n-submanifolds with flat, non-degenerate normal bundle in anti-de Sitter space H1(2n-1)(-1), where G(n-1,n-1)1,1 = O(2n - 2, 2)/O(n - 1,1)×O(n-1, 1).
基金supported by the National Basic Research Program of China (No.2010CB327604)the Jiangsu Meteorological Observation and Information Processing Key Laboratory Open Subject (No.KDXS1107)+2 种基金the College Science Research Program of Hebei Province (No.Z2010336)the Science and Technology Supporting Projects of Qinhuangdao (No.201101A093)the Doctorate Foundation of Yanshan University
文摘Novel highly nonlinear photonic crystal fibers(HN-PCFs) with flattened dispersion are proposed by omitting 19 air holes as the fiber core.The simulation results show that the high nonlinearity and the flattened dispersion can be achieved simultaneously by employing only two types of air holes in the cladding.To reduce the confinement loss,the modified designs are presented.The confinement loss is below 0.1 dB/km at 1.55 μm,when seven layers of air-hole rings are introduced to the cladding.After modifying,the dispersion can change from-0.5 ps/(nm.km) to+0.5 ps/(nm.km) in the range from 1.35 μm to 2.06 μm,and the effective mode area is as low as 2.27 μm 2 at 1.55 μm.
基金Islamic Azad University,Khorram Branch,for Financial support
文摘We study the Bell's inequality and multipartite entanglement generation for initially maximally entangled states of free Dirac field in a non inertial frame and asymptotically flat Robertson–Walker space-time.For two qubit case,we show that the Bell's inequality always is violated as measured by the accelerated observers which are in the causally connected regions.On the other hand,for those observers in the causally disconnected regions inequality is not violated for any values of acceleration.The generated three qubit state from two qubit state due to acceleration of one parties has a zero 3-tangle.For a three qubit state,the inequality violated for measurements done by both causally connected and disconnected observers.Initially GHZ state with non zero 3-tangle,in accelerated frame,transformed to a four qubit state with vanishing 4-tangle value.On the other hand,for a W-state with zero 3-tangle,in non inertial frame,transformed to a four qubit state with a non-zero 4-tangle acceleration dependent.In an expanding space-time with asymptotically flat regions,for an initially maximally entangled state,the maximum value of violation of Bell's inequality in the far past decreased in the far future due to cosmological particle creation.For some initially maximally entangled states,the generated four qubit state due to expansion of space-time,has non vanishing 4-tangle.
基金supported by the National Natural Science Foundation of China(No.60778017)the Shandong Provincial Natural Science Foundation of China(No.ZR2011FM015)the Research Foundation of Liaocheng University of China
文摘We propose the sub-picosecond chirped soliton pulse propagation in copcave-dispersion-flattened fibers （CDFF）. The effects of pulse characteristics and the fiber dispersion parameters on propagation characteristics of the chirped soliton pulse are numerically investigated in the CDFF by the split-step Fourier method （SSFM）. The unchirped soliton pulse can stably propagate with unchanged pulse width in the CDFE The temporal full width at half maximum （FWHM） of the chirped soliton performs a damped oscillation with the increase of propagation distance. The period and amplitude of the oscillation increase with the increase of the chirp parameter ｜C｜. The effect of high-order dispersion （β3-β6） on soliton propagation characteristics can be neglected. The soliton pulse slightly broadens with the increase of propagation distance and still maintains soliton characteristics when the fiber loss （ATT） is further considered. The variation of root-meansquare （RMS） spectral width with propagation distance is opposite to that of the temporal width. The output spectrum of soliton has a single peak for the unchirped case, while has multi-peak for chirped case. The temporal width of the soliton obviously increases with the increase of the initial width, decreases with the increase of dispersion peakD0 of the fiber, and slightly increases with the decrease of dispersion coefficients k1 and k2 of the fiber.
