Anna Vershynina, University of Houston
Coherence describes the existence of quantum interference. The most used one is a relative entropy of coherence defined as the minimal distance between a state and the set of incoherent states while the distance is measured by the relative entropy. This closest incoherent state is the dephased state, and the coherence can also be written as the entropy difference between a state and its dephased state. Having these three equivalent definitions of the relative entropy of coherence the natural question is, if we generalize this situation to Tsallis or Renyi entropies, would it define good coherence measures? In this talk I will review five known definitions of coherence based on Renyi and Tsallis entropies, and will define a new Tsallis coherence as the entropy difference between a state and the closest incoherent state.