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Modified correlation entropy of a gated nanowire system described by a numerically determined non‐equilibrium many‐body statistical operator
Author(s) -
Castelo José María,
Indlekofer Klaus Michael
Publication year - 2015
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.201552174
Subject(s) - statistical physics , entropy (arrow of time) , physics , hamiltonian (control theory) , joint quantum entropy , parameterized complexity , operator (biology) , quantum mechanics , mathematics , chemistry , quantum , combinatorics , mathematical optimization , repressor , transcription factor , biochemistry , gene
A numerical correlation measure of the interacting electrons in a semiconductor nanowire‐based field‐effect transistor (NWFET) is presented, which solely quantifies correlation whether the preparation of the system is pure or mixed, in contrast to the single‐particle‐reduced entropy, which depends on the degree of correlation and mixture as well. This numerical measure, which is termed modified correlation entropy Δ S , is based on the concept of von Neumann entropy, whose calculation is dependent on the non‐equilibrium many‐body statistical operator of the system. Therefore, we present a numerical approach to construct such a non‐equilibrium many‐body statistical operatorρ ˆ rel for relevant quasi‐bound electronic states in a NWFET. As a constraint forρ ˆ rel , we assume that the single‐particle density matrix ρ 1 is a given quantity, resulting from a non‐equilibrium Green's function (NEGF) calculation for the NWFET for a given set of applied voltages. The eigenbasis ofρ ˆ rel is assumed to be identical to the eigenbasis of the projected many‐body HamiltonianH ˆ rel within a relevant Fock subspace of the quasi‐bound subsystem. As for the eigenvalues w N ofρ ˆ rel , we furthermore assume that w N have a generalized Boltzmann form, parameterized by effective electrochemical potentials of natural orbitals and a given temperature. Onceρ ˆ rel is obtained, we calculate and compare the modified entropy Δ S , the single‐particle‐reduced entropy S 1 and the von Neumann entropy S for two different transport regimes of the NWFET.