Efficient remote preparation of arbitrary twoand three-qubit states via the χ state

The application of χ state are investigated in remote state preparation(RSP). By constructing useful measurement bases with the aid of Hurwitz matrix equation, we propose several RSP schemes of arbitrary two- and three-qubit states via the χ state as the entangled resource. It is shown that the original state can be successfully prepared with the probability100% and 50% for real coefficients and complex coefficients, respectively. For the latter case, the special ensembles with unit success probability are discussed by the permutation group. It is worth mentioning that the novel measurement bases have no restrictions on the coefficients of the prepared state, which means that the proposed schemes are more applicable.     

Deterministic assisted clone of an unknown four-particle entangled cluster-type state

Two deterministic schemes are proposed to realize the assisted clone of an unknown four-particle entangled cluster- type state. The schemes include two stages. The first stage requires teleportation via maximal entanglement as the quantum channel. In the second stages of the protocols, two novel sets of mutually orthogonal basis vectors are constructed, With the assistance of the preparer through a four-particle or two-step two-particle projective measurement under these bases, the perfect copy of an original state can be produced. Comparing with the previous protocols which produce the unknown state and its orthogonal complement state at the site of the sender, the proposed schemes generate the unknown state deterministically.     

复齐性有界域的全纯自同构群的显式

熟知最大连通全纯自同构群Aut(D)(0)是三角群T(D)和复齐性有界域D中一固定点的最大连通迷向子群Iso(D)(0)的半直乘积,而且任一复齐性有界域都全纯同构于正规Siegel域D(V_N,F)．本文给出T(D(V_N,F))和Iso(D(V_N,F))(0)中全纯自同构的明显表达式,其中G(0)是Lie群G的单位连通分支．