### ?

## Dynamic spin injection into a quantum well coupled to a s pin-split bound state

We present a theoretical analysis of dynamic spin injection due to spin-dependent tunneling between a quantum

well (QW) and a bound state split in spin projection due to an exchange interaction or external magnetic ﬁeld. We

focus on the impact of Coulomb correlations at the bound state on spin polarization and sheet density kinetics of

the charge carriers in the QW. The theoretical approach is based on kinetic equations for the electron occupation

numbers taking into account high order correlation functions for the bound state electrons. It is shown that the

on-site Coulomb repulsion leads to an enhanced dynamic spin polarization of the electrons in the QW and a delay

in the carriers tunneling into the bound state. The interplay of these two effects leads to nontrivial dependence

of the spin polarization degree, which can be probed experimentally using time-resolved photoluminescence

experiments. It is demonstrated that the inﬂuence of the Coulomb interactions can be controlled by adjusting the

relaxation rates. These ﬁndings open a new way of studying the Hubbard-like electron interactions experimentally.