Statistical measure of complexity and correlated behavior of Fermi systems

Abstract

We apply the statistical measure of complexity, introduced by López-Ruiz, Mancini and Calbet (LMC), to uniform Fermi systems. We investigate the connection between information and complexity measures with the strongly correlated behavior of various Fermi systems as nuclear matter, electron gas and liquid helium. We examine the possibility that LMC complexity can serve as an index quantifying correlations in the specific system and to which extent could be related with experimental quantities. Moreover, we concentrate on thermal effects on the complexity of ideal Fermi systems. We find that complexity behaves, both at low and high values of temperature, in a similar way as the specific heat. PACS number(s): 05.30. Fk, 89.70.Cf, 05.90.+m

Nonequilibrium thermodynamics with binary quantum correlations

“…Entropy The entropy as a measure of complexity, or inversely as the loss of information, plays a central role in processes like nuclear or cluster reactions, where the kinetic and correlation energy of projectile and target particles transform into heat. In nuclear matter, mainly the single-particle entropy [60][61][62][63][64] is discussed as it is in ultra-cold atoms 65 . The equilibrium entropy has been given in a form of cluster expansion where the twoparticle part is represented by the two-particle correla-tion function 66 which has been calculated numerically for different systems 67,68 .…”