https://doi.org/10.1140/epjb/e2018-90126-5
Regular Article
An ab-initio approach to describe coherent and non-coherent exciton dynamics★
1
European Theoretical Spectroscopy Facility (ETSF) and CNR-ISM, Division of Ultrafast Processes in Materials (FLASHit),
Area della Ricerca di Roma 1,
Monterotondo Scalo, Italy
2
Dipartimento di Fisica and European Theoretical Spectroscopy Facility (ETSF), Università di Roma Tor Vergata,
Via della Ricerca Scientifica 1,
00133
Roma, Italy
3
INFN, Sezione di Roma Tor Vergata,
Via della Ricerca Scientifica 1,
00133
Roma, Italy
a e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
Received:
2
March
2018
Received in final form:
3
May
2018
Published online: 1
August
2018
Abstract
The use of ultra-short laser pulses to pump and probe materials activates a wealth of processes which involve the coherent and non coherent dynamics of interacting electrons out of equilibrium. Non equilibrium (NEQ) many body perturbation theory (MBPT) offers an equation of motion for the density–matrix of the system which well describes both coherent and non coherent processes. In the non correlated case there is a clear relation between these two regimes and the matrix elements of the density–matrix. The same is not true for the correlated case, where the potential binding of electrons and holes in excitonic states need to be considered. In the present work we discuss how NEQ-MBPT can be used to describe the dynamics of both coherent and non-coherent excitons in the low density regime. The approach presented is well suited for an ab initio implementation.
Contribution to the Topical Issue “Special issue in honor of Hardy Gross”, edited by C.A. Ullrich, F.M.S. Nogueira, A. Rubio, and M.A.L. Marques.
© EDP Sciences / Società Italiana di Fisica / Springer-Verlag GmbH Germany, part of Springer Nature, 2018
