Quantum Secure Direct Communication By Using Multi-particle High-dimensional Quantum States

Quantum Information Science (QIS) is a new subject combined with Quantum Mechanics and Information Science, which has made a surprise progress both in theoretical and experimental field in the past two decades. It has created many miracles, such as absolute secure quantum key, quantum dense coding, quantum teleportation, especially quantum secure direct communication which is proposed recently. With the research of related theories and the development of hardware technology, improving the security and accurately during the information transmitting becomes an important aspect in communication technology. Quantum secure direct communication is an important part of quantum communication. Briefly, two parties (sender and receiver) share a pair of entangled qubits in the same state. According to the messages, the sender performs one of the unitary operations on the particles in her site. Because of the properties of the entanglement, the operation leads to a change of the particles in the receiver's site. Then, the receiver can obtain information from the measurement results by measure his particles in proper measurement basis (MB). This is so called"Quantum Secure Direct Communication".In this article we devote to study the quantum secure direct communication by using multi-particle high-dimensional quantum states, and the main contents are given as follows:1. We present a quantum secure direct communication based on rearranging order of qutrits. On this basis, we present controlled secure direct communications by using three-particle three-dimensional entanglement states and cluster states. We also show our schemes are secure if eavesdroppers in the quantum channel.2. We proposed protocols which realize quantum dialogue and controlled quantum dialogue by using high-dimensional entangled state. These communications are secure based on the order rearrangement of qutrits and quantum entanglement swapping.