Qubit thermodynamics

Abstract

Entropy had been rooted in thermodynamics. We have to explore this background of the microscopic q-entropy. We do not hesitate to apply thermodynamics to a single qubit if we recall the classical ideal gas where thermodynamical equations are satisfied by the microscopic state of each single molecule. Since thermal environment is natural for a physical qubit, further notions of thermodynamics, like thermalization, refrigeration, or the Carnot cycle, apply to qubits. Their significance for q-information is a delicate challenge. © 2011 Springer-Verlag Berlin Heidelberg.