Brief Introduction to Photonic Quantum Information Research

Binbin Chen, Jing Wang, Yunsen Zhou

Abstract The development of quantum information science has brought great changes to the fields of computer and communication, and deepened people’s understanding of basic physical problems. The core problems of overcoming decoherence, preparing and manipulating quantum states are quantum control problems in essence, so the research on quantum control will attract more and more attention and be important in the development of quantum information. This paper studies several applications of quantum Lyapunov control and quantum feedback control in quantum information processing by using Schrodinger equation, and some principal equations as tools for finite-dimensional systems. In this paper, a brief introduction of quantum control and its applications is presented to review the recent development and its prospect.

Teodor Strömberg

Yoshihiro Nambu, Hideo Kosaka

Quantum cryptography provides us with a method for two remote users to communicate in an unconditionally secure way. In this paper, we present a brief introduction of this new technique and activities in our laboratory to develop a practical cryptographic system using photonic technologies.

Sebastian Malewicz

Linda Sansoni

Cao Huaixi

In the classical information theory,coding state can be accurately copied and distinguished;while in quantum information,it is impossible to copy,delete and distinguish non-orthogonal states due to the superposition of states.However,discrimination and cloning of quantum states have extensive applications in the new-type quantum information science such as receiving and eavesdropping in the quantum cryptography and so on.In this review paper,the mathematical concepts and the related research results about discrimination and cloning of quantum states are briefly introduced.