2.1. 99-02-16796
2.2. Suris Robert Arnol'dovich
2.3. Theoretical investigations of the electronic and optical
     properties and the processes of growth of semiconductor
     heterostructures with quantum dots and strained quantum 
     wells.
2.4. 2001
2.5. 2
2.6. 
     Theory of threshold characteristics of QD lasers is 
     generalized for the case of multiple radiative transitions. 
     The effect of microscopic parameters on the gain is 
     discussed. The conditions for a smooth or step-like change 
     in the lasing wavelength with the losses are formulated. 
     Threshold characteristics of a laser based on self-assembled 
     pyramidal InAs QDs in GaAs matrix are simulated. A small 
     overlap integral for optical transitions in such QDs (and 
     hence large spontaneous radiative lifetime) is shown to be a 
     main possible reason for a low value of the modal gain of 
     the respective structure, which is deficient to attain 
     lasing at moderately short (several hundreds of micrometers) 
     cavity lengths.

     Theory of multimode generation caused by the effect of 
     spatial hole burning in QD lasers is generalized for low 
     temperatures. The multimode generation threshold is shown 
     to be controlled by the spontaneous lifetime in QDs and is 
     essentially temperature-independent (in contrast to high-
     temperature regime when it is controlled by the nonvanishing 
     times of thermally excited escapes of carriers from QDs and 
     depends exponentially on the temperature). Ways to optimize 
     the QD laser, aimed at maximizing the multimode generation 
     threshold, are outlined.

     Theoretical analysis of carrier photoexcitation from levels 
     in QDs to continuous-spectrum states during the laser 
     operation is given. The light absorption in the process of 
     carrier photoexcitation is shown to be essential in the 
     quantum dot laser operation only at very low total losses, 
     e.g., for the case of long-cavities.

     Simple variational function, well deckribing X+ and X- 
     trions in two-dimension quantum well, is found.

     We have continued the theoretical investigation of kinetic 
     properties of carriers in Quantum Dot Superlattices of 
     various dimesionality (1D, 2D, 3D QDSL). The qualitative 
     analysis of the dependence of phase relaxation time of Bloch 
     oscillating electrons on the dc electric field strength and 
     orientation and on the values of resonant tunneling matrix 
     elements among quantum dots have been developed. We have 
     found the conditions when dephasing of Bloch oscillations is 
     few degrees of magnitude slower than that for quantum well 
     superlattices. Such a small dephasing time opens a 
     possibility of observation and practical usage of Bloch 
     oscillations at the enviropment temperature.

     The wave functions of carriers in quantum wells with the 
     existence of the transversal magnetic field were found in 
     the framework of the 4-band Kane model. The temperature and 
     magnetic field dependences of Auger coefficient in such 
     systems were studied. The wave functions of carriers in 
     cylindrical quantum wires and spherical quantum dots were 
     found in the framework of the 4-band Kane model. The 
     dependences of Auger coefficient in quantum dots on 
     the temperature, heights of heteroboundaries and radius 
     were studied.

     The investigations of defect evolution in silicon carbide 
     under Al and N ion irradiation has been carried our taking 
     into account  stress field due to different clusters of 
     radiation defects.


2.7. A.F. Ioffe Physico-Technical Institute of Russian Academy of 
     Sciences