# Many-body effective mass enhancement in a two-dimensional electron liquid

Please use this identifier to cite or link to this item: http://hdl.handle.net/10355/7782

 Title: Many-body effective mass enhancement in a two-dimensional electron liquid Author: Asgari, R.; Davoudi, B.; Polini, Marco; Tosi, M. P.; Giuliani, Gabriele, 1953-; Vignale, Giovanni, 1957- Keywords: Mesoscopic Systems Date: 2004-12-23 Publisher: arXiv Citation: arXiv:cond-mat/0412665v1 Abstract: Motivated by a large number of recent magnetotransport studies we have revisited the problem of the microscopic calculation of the quasiparticle effective mass in a paramagnetic two-dimensional (2D) electron liquid (EL). Our systematic study is based on a generalized $GW$ approximation which makes use of the many-body local fields and takes advantage of the results of the most recent QMC calculations of the static charge- and spin-response of the 2D EL. We report extensive calculations for the many-body effective mass enhancement over a broad range of electron densities. In this respect we critically examine the relative merits of the on-shell approximation, commonly used in weak-coupling situations, {\it versus} the actual self-consistent solution of the Dyson equation. We show that already for $r_s \simeq 3$ and higher, a solution of the Dyson equation proves here necessary in order to obtain a well behaved effective mass. Finally we also show that our theoretical results for a quasi-2D EL, free of any adjustable fitting parameters, are in good qualitative agreement with some recent measurements in a GaAs/AlGaAs heterostructure. URI: http://hdl.handle.net/10355/7782