ar X iv : c on d - m at / 0 30 13 88 v 1 2 1 Ja n 20 03 Optical Spin Orientation under Inter - and Intra - Subband Transitions in QWs

ar X iv : c on d - m at / 0 30 13 89 v 1 2 1 Ja n 20 03 Spin - photocurrent in p - SiGe quantum wells under terahertz laser irradiation

A detailed study of the circular photogalvanic effect (CPGE) in SiGe structures is presented. It is shown that the CPGE becomes possible due to the built-in asymmetry of quantum wells (QWs) in compositionally stepped samples and in asymmetrically doped structures. The photocurrent arises due to optical spin orientation of free carriers in QWs with spin splitting in k-space. It is shown that the...

ar X iv : m at h - ph / 0 30 10 19 v 1 1 5 Ja n 20 03 Which distributions of matter diffract ? — Some answers

Monopolar Optical Orientation of Electronic Spins in Semiconductors

It is shown that absorption of circularly polarized infrared radiation due to intraband (Drude-like) transitions in n-type bulk semiconductors and due to intra-subband or inter-subband transitions in quantum well (QW) structures results in a monopolar spin orientation of free electrons. Spin polarization in zinc-blende-structure based QWs is demonstrated by the observation of the spin-galvanic ...

ar X iv : c on d - m at / 0 30 12 85 v 1 1 6 Ja n 20 03 Polaronic Heat Capacity in The Anderson - Hasegawa Model

An exact treatment of the Anderson Hasegawa two site model, incorporating the presence of superexchange and polarons, is used to compute the heat capacity. The calculated results point to the dominance of the lattice contribution, especially in the ferromagnetic regime. This behavior is in qualitative agreement with experimental findings. PACS No. 63.20. Kr, 75.30. Et, 75.40.-s ∗Electronic addr...

ar X iv : h ep - t h / 03 01 23 5 v 1 2 9 Ja n 20 03 Higher - Spin Theories and Sp ( 2 M ) Invariant Space – Time

Some methods of the " unfolded dynamics " machinery particularly useful for the analysis of higher spin gauge theories are summarized. A formulation of 4d conformal higher spin theories in Sp(8) invariant space-time with matrix coordinates and its extension to Sp(2M) invariant space-times are discussed. A new result on the global characteriza-ton of causality of physical events in the Sp(2M) in...