The reporter recently learned from China University of Science and Technology that Li Chuanfeng, a member of the academic team of Guo Guangcan, has cooperated with foreign research groups to successfully develop a quantum simulator with adjustable photon frequency and phase. Any phase decoherence process can be realized by programming control. Recently published in the international authoritative journal "Nature·Communication".
The basic unit of a classical computer is a bit, and its value can be 0 or 1. The environmental interference causes the value of the bit to change from 0 to 1, and when 1 becomes 0, an error occurs. The basic unit of the quantum computer is a quantum bit, which can be in The superposition state of 0 and 1. Under the environmental interference, even if 0 and 1 can remain unchanged, the qubit will still be wrong, because the environment can cause the phase between 0 and 1 to change, thus changing the entire qubit causes an error, this The process is phase decoherence. How to overcome it is the biggest difficulty encountered in the development of quantum computers. If a fully controllable phase decoherence research platform can be constructed, the development of quantum computers will be promoted.
Li Chuanfeng's research group completed this task in the optical system. They used the polarization of a single photon as a quantum bit, and the frequency of the photon as an environment, constructing a fully controllable phase evolution quantum simulator. The research team designed the smart light path. The frequency distribution of the photons is transformed into a spatial distribution, and the two polarized lights are converted into two parallel light inputs to the spatial light modulator. The arbitrary frequency distribution and phase distribution of the photons can be constructed by programming control of the spatial light modulator. To achieve an arbitrary phase decoherence process. As an example, the research team used a controllable phase decoherence quantum simulator to study a qubit coupled to the transverse field Ising chain, showing its paramagnetic phase. Three completely different phase decoherence processes of ferromagnetic phase and phase transition point.
