Reduce coherence loss in coherence-assisted transformation

Abstract

We discuss the coherence-assisted transformation of pure coherent states under incoherent operations and show that the amount of coherence loss can be reduced with the help of the auxiliary coherent state. Starting with the simplest case i.e., the main coherent state and auxiliary coherent state are both 2×2 dimensional, we compare the change of coherence before and after the transformation and find that the amount of coherence loss can be reduced due to the increase of the coherence of auxiliary coherent state. In general, when the main coherent state and auxiliary coherent state are high-dimensional, the result is also true. For the coherence of auxiliary coherent state is increased, we can get the maximally coherent state at some conditions, this case can be viewed as a new way for the distillation of coherent state. These interesting results of coherence transformation will give us a better understanding of the resource manipulation.