  The entropy of a system gives a powerful insight into its microscopic degrees
of freedom, however standard experimental ways of measuring entropy through
heat capacity are hard to apply in mesoscale and nanoscale systems, as they
require the measurement of increasingly small amounts of heat. This problem
calls for radically different measurement methods that do not suffer from
decreasing accuracy with the decreasing size of the system. For nanoelectric
devices in the state of Coulomb blockade, with only two energetically
accessible charge states, two purely electric, size-independent methods of
measuring the entropy difference between the charge states have been proposed:
through transport properties and charge balance measurements. We suggest a
self-consistent thermodynamic framework for the treatment of entropy in
Coulomb-blocked electric nanodevices which incorporates both existing entropy
measurement methods, generalises them, and expands to systems with arbitrarily
complex microstates corresponding to each charge state.
