Multi-output quantum teleportation of different quantum information with an IBM quantum experience

:Multicast-based quantum teleportation(QT) is extensively used in quantum information transmission where a sender sends different information to multiple receivers at the large distance through the quantum entangled channel. In this paper, we introduce the multi-output QT scheme, which deals with the situation that the synchronous transfer of the arbitrary m-and(m+1)-qubit GHZ-class states from one sender to two receivers. Notably, the requirement about synchronous diverse information transmission is satisfied in our scheme with high efficiency. Moreover, we demonstrate the implementation of the special case of above quantum multi-output teleportation scheme on a sixteenqubit quantum computer and a 32-qubit simulator provided by IBM quantum platform, then discuss it in four types of noisy environments, and calculate the fidelities of the output states.

Experimental realization of quantum controlled teleportation of arbitrary two-qubit state via a five-qubit entangled state

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.

Homomorphic encryption experiments on IBM＇s cloud quantum computing platform

Quantum computing has undergone rapid development in recent years. Owing to limitations on scalability, personal quantum computers still seem slightly unrealistic in the near future. The first practical quantum computer for ordinary users is likely to be on the cloud. However, the adoption of cloud computing is possible only if security is ensured. Homomorphic encryption is a cryptographic protocol that allows computation to be performed on encrypted data without decrypting them, so it is well suited to cloud computing. Here, we first applied homomorphic encryption on IBM＇s cloud quantum computer platform. In our experiments, we successfully implemented a quantum algorithm for linear equations while protecting our privacy. This demonstration opens a feasible path to the next stage of development of cloud quantum information technology.