Relative Rényi entropy and fidelity susceptibility
1 Department of Theoretical Physics, University of Debrecen - H-4010 Debrecen, Hungary
2 Instituto Carlos I de Física Teórica y Computacional and Departamento de Física Atómica, Molecular y Nuclear, Universidad de Granada - Fuentenueva s/n, 18071 Granada, Spain
Received: 8 January 2015
Accepted: 8 March 2015
It is shown that there is a linear relation between the relative Rényi entropy and the density functional fidelity susceptibility. The derivative of the relative Rényi entropy with respect to the Rényi parameter α is also proportional to the density functional fidelity susceptibility. The benefit of these relations is illustrated for the Dicke model (considering a numerical study and a variational analytical approximation). These relations are useful to detect the second-order QPT in this model.
PACS: 05.30.Rt – Quantum phase transitions / 89.70.Cf – Entropy and other measures of information
© EPLA, 2015