Time-resolved Kerr reflectivity of two-dimensional electron gases in II-VI semiconductors provides a direct measure of electron spin precession and relaxation over a temperature range from 4 to 300 kelvin. The introduction of n-type dopants increases the electronic spin lifetimes several orders of magnitude relative to insulating counterparts, a trend that is also observed in doped bulk semicon...

Temperature and doping dependencies of electron mobility in InP semiconductor has been calculated using an iterative technique. The following scattering mechanisms, i.e, impurity, polar optical phonon, acoustic phonon and piezoelectric are included in the calculation. It is found that the electron mobility decreases monotonically as the temperature increases from 100 K to 600 K. The low tempera...

The radical pair recombination of an intramolecular electron-transfer system containing a transition metal moiety has been addressed by femtosecond spectroscopy. The radical pair is formed by ultrafast electron transfer (90 fs) from a ferrocene residue to a photoexcited Nile blue moiety. Its recombination proceeds on the picosecond time scale in a multiexponential fashion. The kinetic pattern i...

results the results showed that compared to the control group, relaxation (23.2) and positive self-talk (21.25) treatment methods alone can reduce pms (p < 0.001). on the other hand, a combined (relaxation + positive self-talk) treatment method (13.75) was more effective in reducing pms compared to relaxation or positive self-talk alone. conclusions it seems that psychological therapy based on ...

Extended electron spin precession in n-type GaAs bulk semiconductors is directly observed by femtosecond time-resolved Faraday rotation in the Voigt geometry. Synchronous optical pumping of the spin system amplifies and sustains spin motion, exposing a regime where spin lifetimes increase tenfold at low fields and exceed 100 ns at zero field. Precise studies in field and temperature provide clu...

Gate control of dynamic nuclear polarization under optical orientation is demonstrated in a Schottky-gated n-GaAs/AlGaAs (110) quantum well by time-resolved Kerr rotation measurements. Spin relaxation of electrons due to mechanisms other than the hyperfine interaction is effectively suppressed as the donor induced background electron density is reduced from metallic to insulating regimes. Subse...

Nanosecond time-resolved absorption studies in a magnetic field ranging from 0 to 2.0 T have been performed on a series of covalently linked donor(PXZ)-Ru(bipyridine)3-acceptor(diquat) complexes (D-C2+-A2+). In the PXZ moiety, the heteroatom (X = O (oxygen), T (sulfur), and S (selenium)) is systematically varied to study spin-orbit coupling effects. On the nanosecond time scale, the first detec...

Electronic relaxation dynamics subsequent to s→p excitation of the excess electron in large anionic water clusters, H2O n − and D2O n − with 25 n 200, were investigated using time-resolved photoelectron imaging. Experimental improvements have enabled considerably larger clusters to be probed than in previous work, and the temporal resolution of the instrument has been improved. New trends are s...