- Quantum Simulation and Computation
- Quantum Mechanics, Thermodynamics, and Information Theory
- Quantum Communication
- Computational Complexity of Physics and Chemistry
- Spintronics

__Professional Activities__

- Member of the editorial board (Quantum Physics section) of
*Scientific Reports*

*Research highlight*

- Demon-like algorithmic quantum cooling [Nature Photonics 8, 113–118 (2014)]

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Maxwell’s demon is a thought experiment in physics, where an intelligent being, or a demon, is able to separate hot and cold gas molecules by conditionally opening and closing a door. Consequently, the entropy of the gas system decreases “spontaneously”, which would violate the second law of thermodynamics if the entropy gain of the demon is not taken into account. In our work published in __Nature Photonics__, we generalize this idea to the quantum domain; we found that given any quantum state, a quantum circuit can be applied such that the state is in a superposition of a hotter state and a colder state, relative to a Hamiltonian that can be simulated by a quantum computer. One can then perform a projective measurement to obtain either of them probabilistically, in a way similar to that of Maxwell’s demon.

See a related discussion on the connection between heat engines, refrigerators and computation by Seth Llyod in his News and View (also see the Research Highlights by Tim Reid in Nature China). I thank Jin-Shi Xu for providing the picture of Maxwell’s demon above to me, which is also published in many news coverage of our work, including 科学网, 中科大新闻中心 and 人民网.