We have studied experimentally spin-dependent photon echoes from excitons in an InGaAs/GaAs quantum well subject to a transverse magnetic field (Voigt geometry). Larmor precession of the spins of the electron and heavy hole in an exciton leads to a periodic transfer of coherence between bright and dark exciton states. The increase in dephasing time due to the transition to the dark states could be useful for coherent control development. A comprehensive analysis shows a good agreement between a four-wave mixing experiment and the predictions of a theoretical treatment based on a five-level exciton model comprising a ground state and two pairs of bright and dark states. The extracted optical dephasing time of bright and dark excitons is equal to 30 and 130 ps, respectively. Exploiting the photon echo reveals evidence of electron Larmor precession with in-plane g factor |ge| = 0.44 +/- 0.05 and heavy hole precession as well. The precession frequency of the latter depends nonlinearly on the applied magnetic field, and the corresponding g factor reaches a value of |gh,& BOTTOM;| & AP; 0.3 at B = 6 T. Estimates for the heavy hole g-factor spreading as well as the isotropic exchange interaction constant are provided.

We study the quantum beats in the polarization of the two-pulse photon echo from donor-bound exciton ensembles in semiconductor quantum wells. To induce these quantum beats, a sequence composed of a circularly polarized and a linearly polarized picosecond laser pulse in combination with an external transverse magnetic field is used. This results in an oscillatory behavior of the photon echo amplitude, detected in the sigma(+) and sigma(-) circular polarizations, occurring with opposite phases relative to each other. The beating frequency is the sum of the Larmor frequencies of the resident electron and the heavy hole when the second pulse is polarized along the magnetic field. The beating frequency is, on the other hand, the difference of these Larmor frequencies when the second pulse is polarized orthogonal to the magnetic field. The measurement of both beating frequencies serves as a method to determine precisely the in-plane hole g factor, including its sign. We apply this technique to observe the quantum beats in the polarization of the photon echo from the donor-bound excitons in a 20-nm-thick CdTe/Cd0.76Mg0.24 Te quantum well. From these quantum beats we obtain the in-plane heavy-hole g factor g(h) = -0.143 +/- 0.005.

Photon echo from trions and excitons in (In,Ga)As/GaAs quantum dots was studied theoretically and experimentally. Theoretical analysis allowed us to distinguish between photon echo signals from excitons and trions measured in the same range of wavelength using different polarization configurations of laser excitation. The theoretical predictions are in good agreement with the experimental data.