Two-copy Quantum Teleportation

We investigate two-copy scenario of quantum teleportation based on Bell measurements. The detailed protocol is presented and the general expression of the corresponding optimal teleportation delity is derived, which is given by the two-copy fully entangled fraction that is invariant under local unitary transformations. We prove that under a speci c case of the protocol, which is signi cant for improving the optimal delity, the set of states with their two-copy fully entangled fractions bounded by a threshold value that required for useful two-copy teleportation is convex and compact. Hence the witness operators exist to separate states that are useful for two-copy teleportation from the rest ones. Moreover, we show that the optimal delity of two-copy teleportation surpasses that of the original one copy teleportation.Comment: 8 pages, 2 figure

Study on Earthquake-Induced Permanent Deformation of Earth-Rockfill Dams

Based on the experimental data, a three-dimensional (3-D) nonlinear effective stress seismic response analysis method of earth-rockfill dams is proposed with the dissipation and diffusion of seismic pore-water pressure been considered. Then a method for evaluating the earthquake-induced permanent deformation of earth-rockfill dams taking into account both residual shear strain and residual volumetric strain is presented. The method proposed by Taniguchi is adopted to evaluate the earthquake-induced permanent deformation caused by residual shear strain. In order to evaluate the earthquake-induced permanent deformation caused by residual volumetric strain, the saturated part and the non-saturated part of the dams are treated separately. An expression of residual volumetric strain for non-saturated soils is proposed by analyzing the test data. As an example, the evaluation of the earthquake-induced permanent deformation of Zipingpu dam is performed

Imaging Neural Activity in the Primary Somatosensory Cortex Using Thy1-GCaMP6s Transgenic Mice

The mammalian brain exhibits marked symmetry across the sagittal plane. However, detailed description of neural dynamics in symmetric brain regions in adult mammalian animals remains elusive. In this study, we describe an experimental procedure for measuring calcium dynamics through dual optical windows above bilateral primary somatosensory corticies (S1) in Thy1-GCaMP6s transgenic mice using 2-photon (2P) microscopy. This method enables recordings and quantifications of neural activity in bilateral mouse brain regions one at a time in the same experiment for a prolonged period in vivo. Key aspects of this method, which can be completed within an hour, include minimally invasive surgery procedures for creating dual optical windows, and the use of 2P imaging. Although we only demonstrate the technique in the S1 area, the method can be applied to other regions of the living brain facilitating the elucidation of structural and functional complexities of brain neural networks