Dynamic quantum secret sharing protocol based on two-particle transform of Bell states

To solve the problems of updating sub-secrets or secrets as well as adding or deleting agents in the quantum secret sharing protocol, we propose a two-particle transform of Bell states, and consequently present a novel dynamic quantum secret sharing protocol. The new protocol can not only resist some typical attacks, but also be more efficient than the existing protocols. Furthermore, we take advantage of the protocol to establish the dynamic secret sharing of a quantum state protocol for two-particle maximum entangled states.

Remote preparation of a Greenberger-Horne-Zeilinger state via a two-particle entangled state

We present two schemes for realizing the remote preparation of a Greenberger-Horne-Zeilinger （GHZ） state. The first scheme is to remotely prepare a general N-particle GHZ state with two steps. One is to prepare a qubit state by using finite classical bits from sender to receiver via a two-particle entangled state, and the other is that the receiver introduces N - 1 additional particles and performs N - 1 controlled-not （C-Not） operations. The second scheme is to remotely prepare an N-atom GHZ state via a two-atom entangled state in cavity quantum electrodynamics （QED）. The two schemes require only a two-particle entangled state used as a quantum channel, so we reduce the requirement for entanglement.

Floquet Bound States in a Driven Two-Particle Bose-Hubbard Model with an Impurity

We investigate how the driving field affects the bound states in the one-dimensional two-particle Bose-Hubbard model with an impurity. In the high-frequency regime, compared with the static lattice [Phys. Rev. Lett. 109 （2012） 116405], a new type of Floquet bound state can be obtained even for a weak particle-particle interaction by tuning the driving amplitude. Moreover, the localization degree of the F1oquet bound molecular state can be adjusted by tuning the driving frequency, and even the Floquet bound molecular state can be changed into the Floquet extended state when the driving frequency is below a critical value. Our results provide an efficient way to manipulate bound states in the many-body systems.

Effect of Quantum Coins on Two-Particle Quantum Walks

We numerically study the effect of the quantum coins on the two-particle quantum walks on an infinite line. Both non-interacting and interacting particles are considered. The joint probability as well as the bunching or anti- bunching behavior are greatly affected by the phase factors in the coin operation. Further, the spatial correlation can be maximized by choosing appropriate coin parameters. The entanglement between the two particles can be adjusted in the same manner.

Probabilistic teleportation of a two-particle entangled state via a partially entangled pair

A scheme for teleporting an unknown two-particle entangled state is proposed. In comparison with the recent protocol （Cola et al., Phys. Lett. A 337 （2005））, the entangled state as quantum channel required by this scheme is a single, partially entangled pair, which is much easier to prepare and maintain. Furthermore, a positive operator valued measure （POVM） is adopted and all kinds of transformations performed by sender and receiver are given in detail. It is shown that the probability of successful teleportation is twice the modulus square of the smaller Schmidt coefficient of the two-particle entangled state, and the fidelity can reach one.

Teleportation of an unknown two-particle entangled state via an asymmetric three-particle entanglement state

In this article, a protocol for the teleportation of an unknown two-panicle entanglement is proposed. The feature of the present protocol is that we utilize an asymmetric threeparticle entangled state as the quantum channel. The optimal discrimination between two nonorthogonal quantum states is adopted. It is shown that an unknown two-particle entangled state can be probabilistically teleported from the sender to the remote receiver on condition that the co-sender successfully collaborates. The fidelity in this protocol is one. In addition, the probability of the successful teleportation is calculated and all kinds of transformations performed by the sender and the receiver are provided in detail.

Two-Particle Boltzmann H-theorem

The celebrated H-theorem of Boltzmann has important physical significance. The H-theorem states that entropy cannot diminish, and that the distribution function f（z, t） must tend towards its equilibrium state.In this paper, using the relationship between solutions of Boltzmann equation and the two-particle Boltzmann equation system, we obtain three forms of Two-Particle Boltzmann H-theorem from the two-particle Boltzmann equation system of BBGGKY hierarchy, and give an application example for the Two-Particle Boltzmann H-theorem. Also, the relation between entropy and the Two-Particle Boltzmann H-theorem is obtained.

Study on open charm hadron production and angular correlation in high-energy nuclear collisions

We study the production and angular correlationof charm hadrons in hot and dense matter produced in high-energy nuclear-nuclear collisions within a multiphasetransport model(AMPT).By triggering additional charm-anticharm quark pair production in the AMPT,the modeldescribes the D^0 nuclear modification factor in the low andintermediate pr regions in Au+Au collisions at√VSNN=200 GeV reasonably well.Further exploration of the D^0 pair azimuthal angular correlation for different centralitiesshows clear evolution from low-multiplicity to high-mul-tiplicity events,which is associated with the number ofcharm quark interactions with medium partons duringAMPT transport.

Secret sharing of quantum information via entanglement swapping

Based on entanglement swapping, a scheme for the secret sharing of an arbitrary two-particle entangled state is proposed. If the controllers do not co-operate with the eavesdropper, the eavesdropper＇s successful probability decreases with the number of the controllers increasing. In addition, only the Bell-state measurements are required to realize the secret sharing scheme.

New two-mode intermediate momentum-coordinate representation with quantum entanglement and its application

We construct four linear composite operators for a two-particle system and give common eigenvectors of those operators. The technique of integration within an ordered product （IWOP） of operators is employed to prove that those common eigenvectors are complete and orthonormal. Therefore, a new two-mode intermediate momentum-coordinate representation which involves quantum entanglement for a two-particle system is proposed and applied to some twobody dynamic problems. Moreover, the pure-state density matrix ｜ξ1,ξ2｜ C,D C,D（ξ1, ξ2｜ is a Radon transform of Wigner operator.

Novel Way to Determine Reaction Plane Dispersion and Its Test to Reaction of 10.6 MeV/u ^(84)Kr on ^(27)Al

A novel way to extract the reaction plane dispersion by combining azimuthal distribu-tion constructed using the experimental measured reaction plane which contains reaction planedispersion and two-particle azimuthal correlation which is free of reaction plane dispersion is de-scribed.This method is applied to the low energy fission reaction 84Kr+27Al at 10.6 MeV/u forlight particles p and a with success.

What Was in the Apparatus before the Click of the Detector?

When a quantum system is described by a superposition of wave-packets, each wave-packet traveling on a separate path, a commonly asked question is why only one of the wave-packets is able to trigger a click in a detector. In the second half of the last century many scientists considered the possibility that not all these wave-packets are identical. Namely, that there exist “full waves” and “empty waves”. The two types of waves were supposed to be identical only in the sense that they are able to produce interference when crossing one another, however, the full wave was supposed to be able to trigger a click in a detector, while the empty wave was supposed to leave the detector silent. The present text describes an experiment in which, for explaining the results, it seems necessary to admit the existence of full and empty waves.

Fringe visibility for two qubits interacting with a macroscopic medium

We study both the two-particle and single-particle fringe visibility in the generalized version of the Nakazato–Pascazio model where two qubits interact with a finite length one-dimensional array.Both the two-particle and single-particle fringe visibilities are investigated with different initial states of the particles spin.For different initial states of the particles spin,the two-particle fringe visibility either decreases or increases over time,and may even decrease first and increase later.Due to the interaction between the particles and the one-dimensional array,the single-particle fringe visibility increases over time when the initial state of the two particles spin is independent.The single-particle fringe visibility is equal to 0 as the two-particle spin is initially in the completely entangled state or in the singlet state.