An explanation of optical unitary transformation is presented for general nonoverlapping-image multimode interference(MMI)couplers with any number of input and output ports.The light transformation in the MMI coupler ...An explanation of optical unitary transformation is presented for general nonoverlapping-image multimode interference(MMI)couplers with any number of input and output ports.The light transformation in the MMI coupler can be considered as an optical field matrix acting on an input light column vector.We investigate the general phase principle of output light image.The complete proof of nonoverlapping-image MMI coupler’s optical unitarity along with the phase analysis of matrix element is provided.Based on a two-dimensional finite-difference time-domain(2 D-FDTD)simulation,the unitary transformation is obtained for a 4×4 nonoverlapping-image MMI coupler within a deviation of 4×10-2 for orthogonal invariance and 8×10-2 for transvection invariance in the C-band spectral range.A compact 1×4 splitter based on cascaded MMI coupler is proposed,showing a phase deviation less than 5.4°while maintaining a low-loss performance in C-band spectra.展开更多
A scheme for teleporting an arbitrary and unknown three-particle state from a sender to either one of two receivers is proposed. The quantum channel is composed of a two-particle non-maximally entangled state and two ...A scheme for teleporting an arbitrary and unknown three-particle state from a sender to either one of two receivers is proposed. The quantum channel is composed of a two-particle non-maximally entangled state and two three-particle non-maximally entangled W states. An arbitrary three-particle state can be perfectly teleported probabilistically if the sender performs three generalized Bell-state measurements and sends to the two receivers the classical result of these measurements, and either one of the two receivers adopts an appropriate unitary transformation conditioned on the suitable measurement outcomes of the other receiver. All kinds of unitary transformations are given in detail.展开更多
Utilizing the generalized measurement described by positive operator-wlued measure, this paper comes up with a protocol for teleportation of an unknown multi-particle entangled （GHZ） state with a certain probability...Utilizing the generalized measurement described by positive operator-wlued measure, this paper comes up with a protocol for teleportation of an unknown multi-particle entangled （GHZ） state with a certain probability. The feature of the present protocol is to weaken requirement for the quantum channel initially shared by sender and receiver. All unitary transformations performed by receiver are summarized into a formula. On the other hand, this paper explicitly constructs the efficient quantum circuits for implementing the proposed teleportation by means of universal quantum logic operations in quantum computation.展开更多
This paper proposes a scheme for teleporting a kind of essential three-particle non-symmetric entangled state, which is much more valuable than a GHZ and W state for some applications in quantum information processing...This paper proposes a scheme for teleporting a kind of essential three-particle non-symmetric entangled state, which is much more valuable than a GHZ and W state for some applications in quantum information processing. In comparison with previous proposal of teleportation, the resources of entangled states as quantum channel and the number of classical messages required by our scheme can be cut down. Moreover, it is shown that there exists a class of transformations which ensure the success of this scheme, because the two-particle transformation performed by the receiver in the course of teleportation may be a generic two-particle operation instead of a control-NOT （CNOT） operation. In addition, all kinds of transformations performed by sender and receiver are given in detail.展开更多
We propose a scheme to realize the nonlocal quantum entanglement of three three-level particles by using a threeparticle entangled state of three levels as a quantum channel with the aid of some local unitary transfor...We propose a scheme to realize the nonlocal quantum entanglement of three three-level particles by using a threeparticle entangled state of three levels as a quantum channel with the aid of some local unitary transformations. This scheme can be directly generalized to the nonlocal quantum entanglement of N three-level particles.展开更多
A three- and an （N＋ 1）-party dense coding scheme in the case of non-symmetric Hilbert spaces of the particles of a quantum channel are investigated by using a multipartite entangled state. In the case of the （N ...A three- and an （N＋ 1）-party dense coding scheme in the case of non-symmetric Hilbert spaces of the particles of a quantum channel are investigated by using a multipartite entangled state. In the case of the （N ＋ 1）-party dense coding scheme, we show that the amount of classical information transmitted from N senders to one receiver is improved.展开更多
Utilizing a three-particle W state, we come up with a protocol for the teleportation of an unknown two-particle entangled state. It is shown that the teleportation can be deterministically and exactly realized. Moreov...Utilizing a three-particle W state, we come up with a protocol for the teleportation of an unknown two-particle entangled state. It is shown that the teleportation can be deterministically and exactly realized. Moreover, two-particle entanglement teleportation is generalized to a system consisting of many particles via a three-particle W state and a multi-particle W state, respectively. All unitary transformations performed by the receiver are given in a concise formula.展开更多
This paper presents a scheme for probabilistic remote preparation of a three-particle entangled Greenberger-Horne-Zeilinger （GHZ） state via three-particle orthonormal basis projective measurement, and then directly ...This paper presents a scheme for probabilistic remote preparation of a three-particle entangled Greenberger-Horne-Zeilinger （GHZ） state via three-particle orthonormal basis projective measurement, and then directly generalize the scheme to multi-particle case. It is shown that by using N pairs of bipartite non-maximally entangled states as the quantum channel and N-particle orthonormal basis projective measurement, the multi-particle remote preparation can be successfully realized with a certain probability.展开更多
Using unitary transformations, this paper obtains the eigenvalues and the common eigenvector of Hamiltonian and a new-defined generalized angular momentum （Lz） for an electron confined in quantum dots under a unifor...Using unitary transformations, this paper obtains the eigenvalues and the common eigenvector of Hamiltonian and a new-defined generalized angular momentum （Lz） for an electron confined in quantum dots under a uniform magnetic field （UMF） and a static electric field （SEF）. It finds that the eigenvalue of Lz just stands for the expectation value of a usual angular momentum lz in the eigen-state. It first obtains the matrix density for this system via directly calculating a transfer matrix element of operator exp（-βH） in some representations with the technique of integral within an ordered products （IWOP） of operators, rather than via solving a Bloch equation. Because the quadratic homogeneity of potential energy is broken due to the existence of SEF, the virial theorem in statistical physics is not satisfactory for this system, which is confirmed through the calculation of thermal averages of physical quantities.展开更多
基金Project supported by the National Key Research and Development Program of China(Grant No.2018YFB2200202)the National Natural Science Foundation of China(Grant No.61804148)
文摘An explanation of optical unitary transformation is presented for general nonoverlapping-image multimode interference(MMI)couplers with any number of input and output ports.The light transformation in the MMI coupler can be considered as an optical field matrix acting on an input light column vector.We investigate the general phase principle of output light image.The complete proof of nonoverlapping-image MMI coupler’s optical unitarity along with the phase analysis of matrix element is provided.Based on a two-dimensional finite-difference time-domain(2 D-FDTD)simulation,the unitary transformation is obtained for a 4×4 nonoverlapping-image MMI coupler within a deviation of 4×10-2 for orthogonal invariance and 8×10-2 for transvection invariance in the C-band spectral range.A compact 1×4 splitter based on cascaded MMI coupler is proposed,showing a phase deviation less than 5.4°while maintaining a low-loss performance in C-band spectra.
文摘A scheme for teleporting an arbitrary and unknown three-particle state from a sender to either one of two receivers is proposed. The quantum channel is composed of a two-particle non-maximally entangled state and two three-particle non-maximally entangled W states. An arbitrary three-particle state can be perfectly teleported probabilistically if the sender performs three generalized Bell-state measurements and sends to the two receivers the classical result of these measurements, and either one of the two receivers adopts an appropriate unitary transformation conditioned on the suitable measurement outcomes of the other receiver. All kinds of unitary transformations are given in detail.
基金Project supported by the National High Technology Research and Development Program of China(Grant No2006AA01Z419)the Major Research Plan of the National Natural Foundation of China(Grant No90604023)+1 种基金the National Laboratory for Modern Communications Science Foundation of China(Grant No9140C1101010601)the Natural Science Foundation of Beijing(Grant No4072020)
文摘Utilizing the generalized measurement described by positive operator-wlued measure, this paper comes up with a protocol for teleportation of an unknown multi-particle entangled （GHZ） state with a certain probability. The feature of the present protocol is to weaken requirement for the quantum channel initially shared by sender and receiver. All unitary transformations performed by receiver are summarized into a formula. On the other hand, this paper explicitly constructs the efficient quantum circuits for implementing the proposed teleportation by means of universal quantum logic operations in quantum computation.
基金Project supported by the National Natural Science Foundation of China （Grants No 60373059）, the National Laboratory for Modern Communications Science Foundation of China （Grant No 51436020103DZ4001）, the Major Research Plan of the National Natural Science Foundation of China （Grant No 90604023）, the National Research Foundation for the Doctoral Program of Higher Education of China （Grant No 20040013007）, and the ISN 0pen Foundation.
文摘This paper proposes a scheme for teleporting a kind of essential three-particle non-symmetric entangled state, which is much more valuable than a GHZ and W state for some applications in quantum information processing. In comparison with previous proposal of teleportation, the resources of entangled states as quantum channel and the number of classical messages required by our scheme can be cut down. Moreover, it is shown that there exists a class of transformations which ensure the success of this scheme, because the two-particle transformation performed by the receiver in the course of teleportation may be a generic two-particle operation instead of a control-NOT （CNOT） operation. In addition, all kinds of transformations performed by sender and receiver are given in detail.
基金Project supported by the National Natural Science Foundation of China （Grant No 60261002） and the Science Foundation of Yanbian University （Grant No 2005-20）.
文摘We propose a scheme to realize the nonlocal quantum entanglement of three three-level particles by using a threeparticle entangled state of three levels as a quantum channel with the aid of some local unitary transformations. This scheme can be directly generalized to the nonlocal quantum entanglement of N three-level particles.
文摘A three- and an （N＋ 1）-party dense coding scheme in the case of non-symmetric Hilbert spaces of the particles of a quantum channel are investigated by using a multipartite entangled state. In the case of the （N ＋ 1）-party dense coding scheme, we show that the amount of classical information transmitted from N senders to one receiver is improved.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 60873191 and 60821001)the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 200800131016)+4 种基金the Key Project of Chinese Ministry of Education (Grant No. 109014)the China Postdoctoral Science Foundation Funded Project (Grant No. 20090450018)the Beijing Natural Science Foundation (Grant No. 4072020)the 111 Project (Grant No. B08004)the National Basic Research Program of China (Grant No. 2007CB311203)
文摘Utilizing a three-particle W state, we come up with a protocol for the teleportation of an unknown two-particle entangled state. It is shown that the teleportation can be deterministically and exactly realized. Moreover, two-particle entanglement teleportation is generalized to a system consisting of many particles via a three-particle W state and a multi-particle W state, respectively. All unitary transformations performed by the receiver are given in a concise formula.
文摘This paper presents a scheme for probabilistic remote preparation of a three-particle entangled Greenberger-Horne-Zeilinger （GHZ） state via three-particle orthonormal basis projective measurement, and then directly generalize the scheme to multi-particle case. It is shown that by using N pairs of bipartite non-maximally entangled states as the quantum channel and N-particle orthonormal basis projective measurement, the multi-particle remote preparation can be successfully realized with a certain probability.
文摘Using unitary transformations, this paper obtains the eigenvalues and the common eigenvector of Hamiltonian and a new-defined generalized angular momentum （Lz） for an electron confined in quantum dots under a uniform magnetic field （UMF） and a static electric field （SEF）. It finds that the eigenvalue of Lz just stands for the expectation value of a usual angular momentum lz in the eigen-state. It first obtains the matrix density for this system via directly calculating a transfer matrix element of operator exp（-βH） in some representations with the technique of integral within an ordered products （IWOP） of operators, rather than via solving a Bloch equation. Because the quadratic homogeneity of potential energy is broken due to the existence of SEF, the virial theorem in statistical physics is not satisfactory for this system, which is confirmed through the calculation of thermal averages of physical quantities.
