Recent progress in quantum information research in the Deapartment of Physics, Tsinghua University

At the occasion of the 60 anniversary of the department, we give a brief introduction of the recent progress on quantum information research over the last few years, including quantum search algorithm, nuclear magnetic resonnace quantum computing experiment, quantum communication theory and experiment. In quantum algorithm study, we put forward the concept of phase matching in quantum searching, corrected a mistake at that time, and furthermore we constructed a quantum search algorithm with 100% successful rate which improves the Grover algorithm. In NMR quantum computing, we have demonstrated several quantum algorithms using 2 to 7 qubits NMR systems. In quantum communication, we have proposed the idea of distributed quantum communication and applied the idea to quantum key distribution, quantum secret sharing and quantum secure direct communication. We have constructed dozens of quantum communication protocols based on this idea. We have demonstrated quantum communication over a 2m distance in free space in laboratory.