Pei-Min Lu

Efficient implementation of the two-qubit controlled phase gate with cross-Kerr nonlinearity

We propose a protocol to direct implement the two-qubit controlled phase gate with cross-Kerr nonlinearity by using the interference of polarized photons. The protocol is based on optical elements, single polarization photons, cross-Kerr nonlinearity and the conventional photon detectors, which are feasible with existing experimental technology. Compared with Zous protocol (Phys. Rev. 2007 A 75 034302), this protocol is to replace the entangled state resources used by Zou with much simpler single-photon resources and has a higher success probability. All these advantages make this protocol more efficient and more convenient than others in the applications in quantum communication.

Effective quantum teleportation of an atomic state between two cavities with the cross-Kerr nonlinearity by interference of polarized photons

In this paper, we propose a protocol for long-distance quantum teleportation of the unknown state of an atom trapped in an optical cavity to a second atom trapped in another distant optical cavity with the help of the cross-Kerr nonlinearity. The setup involves cavities QEDs and linear optical elements, which are feasible with existing experimental technology. More over, in Lame-Dicke limit, the protocol does not require the simultaneous click of the detectors. These make the protocol more realizable in experiments. We also show that the protocol can be successfully realized with a certain probability.

Effective protocol for preparation of four-photon polarization-entangled decoherence-free states with cross-Kerr nonlinearity

We propose an effective protocol for preparation of four-photon polarization-entangled decoherence-free states with quantum nondemolition detectors. The protocol is based on optical elements, single polarization photons, and cross-Kerr nonlinearity, which are feasible with existing experimental technology. Compared with previous protocols, the present one is to replace the entangled-state resources with much simpler single-photon resources and has a higher success probability. All these advantages make this protocol more efficient and more convenient than others in the applications in quantum communication.

Complete polarized photons Bell-states and Greenberger–Horne–Zeilinger-states analysis assisted by atoms

We propose an efficient protocol for complete polarized photons Bell-states and Greenberger–Horne–Zeilinger (GHZ)-states analysis assisted by atoms. With the help of assistant atoms and some simple liner optical elements, the analysis of both polarization Bell states and GHZ states can be performed completely. In our protocol, the assistant atoms are trapped in cavity quantum electronic dynamics (QED), which is feasible with current experimental technology. Moreover, the polarized photons entangled states will not be destroyed in our protocol. Therefore, our scheme might contribute to the quantum communication, quantum computation, and some other fields in quantum information processing.

Remote preparation of N photon GHZ polarization entangled states within a network

We propose a new linear optical protocol for remote state preparation (RSP) between two parties under control of a number of controllers in terms of optical elements. The proposed setup involves simple linear optical elements, a N-photon polarization entangled state, and photon de tectors, witch have been widely used in experiment. The realization of this protocol is appealing due to the fact that quantum state of light is robust against the decoherence and photons are ideal carriers for transmitting quantum information over long distances.

Efficient preparation of Greenberger–Horne–Zeilinger state and W state of atoms with the help of the controlled phase flip gates in quantum nodes connected by collective-noise channels

Noise plays a troublesome role for entanglement generation, because the polarization entanglement of photons can be easily disturbed by the noise. In this paper, we propose a protocol to prepare Greenberger–Horne–Zeilinger state and W state of atoms in quantum nodes connected by collective-noise channels assisted by quantum nondemolition detectors (QNDs) and the controlled phase flip gates. The frequency degrees of freedom are exploited in our protocol. The successful probability of our protocol can reach 100% neglecting the photon loss and assuming that the efficiency of QNDs is 1. Moreover, the number of times of using QNDs is limited, and this makes the protocol quite effective when collective noise is small.

Effective scheme for preparation of a spin-qubit Greenberger–Horne–Zeilinger state and W state in a quantum-dot-microcavity system

We propose a scheme for the preparation of a spin-qubit Greenberger–Horne–Zeilinger (GHZ) state and W state by using quantum dots (QDs) in double-sided optical microcavities with the help of polarized photons. The spin-selective photon reflection from the cavity provides us a perfect way to achieve the scheme by adding some simple linear optical elements and conventional photon detectors. A numerical simulation demonstrates that a perfect scheme of the GHZ state and W state generation can be achieved in one step, and high fidelities can be realized when the side leakage and cavity loss are low, which is feasible in the weak coupling regime. Therefore, our scheme might contribute to quantum communication, quantum teleportation, and some other fields in quantum information processing.

Two-photon phase gate with linear optical elements and atom---cavity system

We propose a protocol for implementing

LINEAR OPTICAL PROTOCOL FOR GENERATION OF W STATE WITHIN A NETWORK

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