基于光子晶体腔链的量子态传输及相位门的实现

Realization of Quantum State Transfer and Phase Gate Based on Photonic Crystal Cavity Chain

研究了光子晶体腔链中任意两奇数节点间量子态传输及相位门实现的问题。发现在绝热条件下,通过求解原子和光子晶体腔链耦合模型的暗态,可实现一维光子晶体耦合腔链中两个腔之间二维量子态的传输及可控相位门。在量子态传输的过程中若原子与腔的耦合强度足够大,腔的激发态的布居数小到可以被忽略。最后讨论了腔链的长度与相位门保真度的关系以及腔链的长度、初态的制备、腔的衰减、原子与腔的耦合强度对量子态传输保真度的影响。

Via two odd nodes of photonic crystal cavities,the mechanism of quantum state transfer and phase gate is studied.It is found that the transfer of the two-dimensional quantum state between two cavities and the controllable phase gate can be realized via one-dimensional photonic crystal cavity chain by solving the dark state of the model of atom coupled with photonic crystal cavities.In the process of quantum state transfer,if the coupling strength between atoms and cavities is large enough,the population of cavity excited states can be neglected.At last,the effect of the length of the cavity chain on the fidelity of the phase gate and the effect of the length of cavity chain,the preparation of the initial state,the attenuation of the cavity and the coupling strength of atoms with the cavity on the fidelity of the quantum state are discussed.