לוח שנה משולב

Spin dynamics in semiconductors is one of the central focuses in semiconductor spintronics, not only due to its relevance in spin-based devices, but also due to its rich phenomena and physics. In most cases, spin dynamics consists of the coherent and dissipative parts. The dissipative part, namely, spin relaxation/dephasing, is
more complicated and richer in its behavior. In this seminar, we introduce our fully microscopic study on spin dynamics via the kinetic spin Bloch equation approach. Specifically, we will discuss spin relaxation/dephasing in bulk III-V semiconductors, quantum wells, dilute magnetic semiconductors, quantum dots. We also studied the spin dynamics in quantum dots and quantum wells under intense terahertz fields where all the high-order sidebands are included exactly. A lot of important results and predictions were obtained, some of which have been confirmed by recent
experiments. The interesting underlying physics is uncovered. Importantly, the carrier-carrier Coulomb scattering is found to be crucial to spin dynamics. The crossover from nondegenerate regime to
egenerate regime leads to rich phenomena in the temperature and density dependences of the spin relaxation time.

Homologous sets of transcription factors direct conserved tissue-specific
gene expression, yet transcription factor binding events diverge rapidly
between closely related species. We used hepatocytes from an aneuploid
mouse strain carrying human chromosome 21 to determine on a chromosomal
scale whether interspecies differences in transcriptional regulation are
primarily directed by human genetic sequence or mouse nuclear environment.
Virtually all transcription factor binding locations, landmarks of
transcription initiation, and the resulting gene expression observed in
human hepatocytes were recapitulated across the entire human chromosome 21
in the mouse hepatocyte nucleus. Thus, in homologous tissues, genetic
sequence is largely responsible for directing transcriptional programs;
interspecies differences in epigenetic machinery, cellular environment, and
transcription factors themselves play secondary roles.

We conjecture a new class of asymptotically locally AdS spacetimes, dual to a deconfined phase of a strongly-coupled field theory on a black hole background. We call these proposed spacetimes black funnels and black droplets, depending of the shape of the bulk black hole horizon. We examine the evidence for the existence of such solutions in lower-dimensional setting, focussing on realizations of funnels and droplets within the AdS C-metric family of solutions.