Source: National Natural Science Foundation of China

Grant No:11725524

Project: Quantun information and the black hole information loss problem

Chief Specialist: Prof.Qingyu Cai

Abstract:

    My research mainly lies in the areas of quantum information theory and its related applications. (1) We systematically study and answer the security issue for quantum key distribution with a two way quantum channel. We prove rigorously for the first time it is unconditionally secure and thus resolve the open problem for two-way quantum cryptography. (2) Using quantum information theory, we discover that there exist information-carrying correlations among Hawking radiations. These correlations carry exactly the amount of information previous considered lost, and the total entropy is
conserved in Hawking radiation process. We show that black hole evaporation process is consistent with unitarity as required by quantum mechanics. We also present a necessary and sufficient condition to falsify whether a Hawking radiation spectrum indicates unitary emission process or not from the perspective of information theory. (3) We study quantum cosmology using quantum trajectory theory. We show that a small true vacuum bubble can expand exponentially due to its quantum potential which plays the role of scalar field or cosmological constant for inflation. We give a dynamical interpretation of the wavefunction of the universe. In total, I have published 44 journal papers, which have been cited more than 1325 times. I have won many awards and recognitions, including the first award for the most influential paper of Chinese Physics Society in 2012, First Award of Essay Competition of the Gravity Research Foundation in 2013, and the Daniel Tsui Fellowship by Hong Kong University in 2014.