Hyper-parallel nonlocal CNOT operation with hyperentanglement assisted by cross-Kerr nonlinearity

Ping Zhou,Li Lv

doi:10.1038/s41598-019-52173-x

Abstract

Implementing CNOT operation nonlocally is one of central tasks in distributed quantum computation. Most of previously protocols for implementation quantum CNOT operation only consider implement CNOT operation in one degree of freedom(DOF). In this paper, we present a scheme for nonlocal implementation of hyper-parallel CNOT operation in polarization and spatial-mode DOFs via hyperentanglement. The CNOT operations in polarization DOF and spatial-mode DOF can be remote implemented simultaneously with hyperentanglement assisited by cross-Kerr nonlinearity. Hyper-parallel nonlocal CNOT gate can enhance the quantum channel capacity for distributed quantum computation and long-distance quantum communication. We discuss the experiment feasibility for hyper-parallel nonlocal gate. It shows that the protocol for hyper-parallel nonlocal CNOT operation can be realized with current technology.

Highlights

Different from previously protocols, we present a protocol for parallel nonlocal implementation of the CNOT operation both in polarization DOF and in spatial-mode DOF by using a two-photon four-qubit hyperentangled state as the quantum channel
The utilization of cross-Kerr nonlinearities has been widely considered in the implementation of quantum information processing both theoretically and experimentally[73,74,75,76,77,78,79]
Our protocol for hyper-parllel nonlocal CNOT operation requires only small phase shift as long as it can be distinguished from zero which makes our protocol for nonlocal CNOT operation in two DOFs more convenient in application than others

Summary

Introduction

The application of quantum entangled state and quantum superposition state in quantum information processing allows the agents in quantum communication to exploit the quantum mechanical phenomena to transmit quantum information securely[1,2,3,4,5,6,7,8,9,10,11,12,13,14], provides quantum computing with computation power which has no counterpart in classical computing[15,16,17,18,19,20,21,22]. Theoretical schemes for remote implementation of quantum operations, especially single-qubit operations, two-qubit CNOT operations and three-qubit gates, have been presented via different quantum channels. CNOT operation can be nonlocal implemented via two bits of classical communication and one ebit of quantum entanglement (a maximally entangled state of two qubits). In 2013, Wang et al proposed a scheme for teleportation of quantum CNOT gate via quantum dots[46]. Presented a scheme for multiparty joint remote implementation of an arbitrary single-qubit operation via single-qubit measurements and quantum entangled channel[48]. Remote implementation of www.nature.com/scientificreports nonlocal CNOT operation between two physical qubits[52] or two logical qubits[53], nonlocal implementation of quantum controlled-SWAP gate have been experimental demonstrated[54]

Methods

Results

Conclusion