International Journal of Quantum Information · 2007 · 23 citations · 22 references
Natural SciencesPhysicsCondensed Matter PhysicsQuantum MechanicsThermodynamicsElectron CorrelationEntropyQuantum StatisticsStatistical MechanicsStatistical ThermodynamicsStrongly Correlated Electron SystemsElectron Correlation EffectsEntropy In Statistical MechanicsMixed Quantum StatesMixed StatesNon-equilibrium Quantum StatesNon-equilibrium Statistical MechanicsNonequilibrium Quantum Statistical MechanicsStatistical Foundations Of Thermodynamics
The "nonfreeness" of a many-fermion state ω is the entropy of ω relative to the free state that has the same 1-particle statistics as ω. The nonfreeness of a pure state is the same as its "particle-hole symmetric correlation entropy", a variant of an established measure of electron correlation. However, nonfreeness is also defined for mixed states, and this allows one to compare the nonfreeness of subsystems to the nonfreeness of the whole. Nonfreeness of a part does not exceed that in the whole; nonfreeness is additive over independent subsystems; and nonfreeness is superadditive over subsystems that are independent on the 1-particle level.
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New Approach to the Theory of Superexchange Interactions
Philip W. Anderson · Physical Review · 1959 · 2.6K citations
The “transition probability” in the state space of a ∗-algebra
Armin Uhlmann · Reports on Mathematical Physics · 1976 · 1.7K citations