Two-qubit controlled phase gate based on two nonresonant quantum dots   trapped in a coupled-cavity array
  We propose a scheme for realizing quantum controlled phase gates with two nonidentical quantum dots trapped in two coupled photonic crystal cavities and driven by classical laser fields under the condition of non-small hopping limit. During the gate operation, neither the quantum dots are excited, while the system can acquire different phases conditional upon the different states of the quantum dots. Along with single-qubit operations, a two-qubit controlled phase gate can be achieved. 
Jian-Qi Zhang, Ya-Fei Yu, Zhi-Ming Zhang
quant-ph