Super dense coding out of thermal equilibrium

Abstract

We have examined the potentiality of superdense coding for a quantum system placed out of
thermal equilibrium. To this aim, the dynamics of two two-level quantum systems are analyzed
and explicit expressions for transition rates are evaluated. The dependence of superdense coding
capacity on initial states is observed and examined for different ratios of anti-symmetric to symmetric
transition rates. The effect of sub-radiant and super-radiant terms is interpreted. The validity of
dense coding is also analyzed for different probability amplitudes and it is perceived that maximally
entangled states show the highest degree of coding capacity. Moreover, the optimal time of coding
capacity is greatest for initially entangled state. This strategy can be relevant to analyze further
applications out of thermal equilibrium.