Full detail of a proposed experiment required for implementing and verifying a theoretical scheme for four-partite splitting and open-destination teleportation of an arbitrary two-qubit photonic state is discussed. In this proposed experiment the quantum channel is provided by a pair of decomposable generalized (G) Bell states, which offer the experimental advantage that they can be very easily generated in photonic experiments. Our experiment is based on generating a two-qubit photonic state by ultrafast spontaneous parametric downconversion in nonlinear crystal and relies on Bell-state measurements, which in this experiment are performed by an optical Bell-state analyzer that can unambiguously determine all four Bell states. In this proposed experiment unitary transformation required at the destination station is implemented using a quantum control NOT gate. We finally show that in our four-partite optical system the two-qubit photonic state originally prepared at a sending station can be experimentally split and subsequently regenerated at any one of the three distinct receiving stations.
Full detail of a proposed experiment required for implementing and verifying a theoretical scheme for four-partite splitting and open-destination teleportation of an arbitrary two-qubit photonic state is discussed. In this proposed experiment the quantum channel is provided by a pair of decomposable generalized (G) Bell states, which offer the experimental advantage that they can be very easily generated in photonic experiments. Our experiment is based on generating a two-qubit photonic state by ultrafast spontaneous parametric downconversion in nonlinear crystal and relies on Bell-state measurements, which in this experiment are performed by an optical Bell-state analyzer that can unambiguously determine all four Bell states. In this proposed experiment unitary transformation required at the destination station is implemented using a quantum control NOT gate. We finally show that in our four-partite optical system the two-qubit photonic state originally prepared at a sending station can be experimentally split and subsequently regenerated at any one of the three distinct receiving stations.
The theory of an experimentally feasible four-partite scheme for splitting and open-destination teleportation of an arbitrary two-qubit state is presented. In this scheme, the quantum channel is provided by a pair of four-qubit generalized (G) Bell-states, which are decomposable. We show that not all possible distributions of entangled qubits to four communicating parties result in successful open-destination teleportation. We theoretically prove that two Bell-state measurements performed by a sender result in splitting, distributing, and locking the two-qubit state among three different receivers. The complete details of the procedure for unlocking the shared two-qubit state and eventually regenerating it at the location of any one of the three receiving stations is theoretically analyzed. This unlocking and regeneration procedure consists of local operations and classical communication (LOCC) performed by the remaining two receivers.
An experimental scheme, its hardware implementation, and procedure for experimental verification of tripartite quantum state sharing and perfect teleportation of the two-qubit photonic state using four different multipartite quantum channels is presented. The four multipartite channels considered are (1) a pair of Greenberger–Horne–Zeilinger triplets, (2) a six-particle cluster state, (3) a highly entangled five-particle Brown state, and (4) a highly entangled six-particle Borras state. In this experiment, optical pulses are delivered by a high repetition rate mode-locked pulsed laser and arbitrary photonic states, in the two-qubit Bloch sphere, are created by the spontaneous parametric down-conversion of optical pulses in a nonlinear crystal. The experimental implementation of the scheme is based on both single-particle and two-particle complete Bell-state measurements, and the unitary transformation required for reconstruction of the qubit is performed using single- and two-qubit operations. Two-qubit operations are implemented using the quantum controlled phase and C-NOT gates. Relative comparison among different multipartite channels along with experimental difficulties and their solutions are also discussed.
Quantum teleportation provides a “bodiless” way of transmitting the quantum state from one object to another, at a distant location, using a classical communication channel and a previously shared entangled state. In this paper, we present a tripartite scheme for probabilistic teleportation of an arbitrary single qubit state, without losing the information of the state being teleported, via a fourqubit cluster state of the form | ϕ > 1234 = α |0000>+ β |1010>+ γ |0101>- η |1111>, as the quantum channel, where the nonzero real numbers α , β , γ , and η satisfy the relation j α j2 + | β | 2 + | γ | 2 + | η | 2 = 1. With the introduction of an auxiliary qubit with state |0>, using a suitable unitary transformation and a positive-operator valued measure (POVM), the receiver can recreate the state of the original qubit. An important advantage of the teleportation scheme demonstrated here is that, if the teleportation fails, it can be repeated without teleporting copies of the unknown quantum state, if the concerned parties share another pair of entangled qubit. We also present a protocol for quantum information splitting of an arbitrary two-particle system via the aforementioned cluster state and a Bell-state as the quantum channel. Problems related to security attacks were examined for both the cases and it was found that this protocol is secure. This protocol is highly efficient and easy to implement.
We propose two schemes for splitting single- and two-qubit states by using four-particle genuine entangled state as the quantum channel. After the sender performs Bell-basis (or three-partite GHZ- basis) measurements on her particles, and the cooperators operate single-particle measurements on their particles, the state receiver can reconstruct the original state of the sender by applying the appropriate unitary operation. In particular, in the scheme for splitting two-qubit state, the receiver needs to introduce an auxiliary particle and carries out a C-NOT operation.
Quantum controlled teleportation is the transmission of the quantum state under the supervision of a third party. This paper presents the theoretical and experimental results of an arbitrary two-qubit quantum controlled teleportation scheme, in which the sender Alice only needs to perform two Bell state measurements and the receiver Bob can perform an appropriate unitary operation to reconstruct the arbitrary two-qubit states under the control of the supervisor Charlie. The operation process of the scheme is verified on the IBM quantum experience platform, and the accuracy of the transmitted quantum state is further checked by performing quantum state tomography. Meanwhile, a good fidelity is obtained by using the theoretical density matrix and the experimental density matrix. A sequence of photonic states is introduced to analyze the possible intercept–replace–resend, intercept–measure–resend, and entanglement–measure–resend attacks on this scheme. The results proved that our scheme is highly secure.
Abstract An elementary tripartite quantum communication network for discrete variables is proposed. In this network three nodes are quantum wired with quantum channel created by a pair of Greenberger–Horne–Zeilinger (GHZ) triplet. We show that in this network by local operations and classical communication an arbitrary two-qubit state can be deterministically teleported from any node to any other node. In this network tripartite teleportation of two-qubit state is achieved by first splitting the qubit into fragments and then at the destination, qubit is re-constructed from the fragments. A high flux source for generation of fully inseparable GHZ photonic quantum channel required for developing an ideal tripartite quantum network is presented. This GHZ source employ a group velocity matched periodically poled potassium titanyl phosphate crystal in pulsed polarization Sagnac interferometer configuration and is based on selecting a three-photon entangled state from the product state of an entangled photon pair and a weak coherent state. This GHZ source generates tripartite entangled photons at telecom wavelength (1584 nm). Genuine entanglement in the generated GHZ state is detected with a witness ( W ) operator. Complete detail of the experimental apparatus required for developing an ideal tripartite quantum communication photonic network, which employ fully inseparable quantum channel, is presented. This quantum network fully operates at wavelength 1584 nm, which occurs in the L-band of the technologically important third telecom window. Success probability for teleportation of two-qubit photonic state within the tripartite quantum network is determined. We show that such quantum network is experimentally feasible. Experimental procedure to unambiguously verify the teleportation of an arbitrary two-qubit photonic state within the network is discussed. It is shown that our scheme can be implemented in a programmed teleportation system and it paves the way towards a large-scale quantum network.