Hello everyone, I am a student major in physical chemistry, but my PhD supervisor ask me to do some theoretical research in the field of quantum open system i.e. quantum transport. I feel it beyond my reach. I've learned that the this field belongs to non equilibrium quantum statistical mechanics and the standard method is the Keldysh's non equilibrium Green's function and Feynman's diagram. But nowadays many groups including mine do not use this standard method. Can someone discuss with me? Maybe I can pm you my msn. I feel very painful and depressed. I need expertise badly! Help me!