We theoretically study the spin dynamics in antiferromagnets (AFs) under influence of an electric current. identify two different sources spin-transfer torques that stem from uniform (\(\boldsymbol{v}_{n}\)) and staggered (\(\boldsymbol{v}_{\ell }\)) electron densities. While former is well recognized, latter often overlooked. show both \(\boldsymbol{v}_{n}\) \(\boldsymbol{v}_{\ell }\) contribu...

We investigate both theoretically and experimentally the decomposition of a fundamental Gaussian beam transmitted behind an absorbing propeller-like object. use Laguerre basis which modes carry orbital angular momentum. The main contributing components correspond to having same rotational symmetry as object, thus enabling pattern recognition. When object is rotated, frequency experiences Dopple...

Wireless channels are characterized among others by their Doppler spectrum. In the cooperative diversity, one of diversity branch may consist of several mobile relays forming multihop link which each hop introduced Doppler shift. With employing amplify-and-forward (AF) relays, the Doppler shift keeps accumulating to the end of the link. Doppler shift value affects the time varying channel rate,...

  Measurement of blood flow and the effects of different factors on tissue blood flow are important fields of research in physiology and pharmacology. So far, different methods have been innovated, using laser light is the Last one. In this article history, principles and specifications of laser technique along with its advantages and disadvantages ( in comparison with other methods) are revie...

Optical Doppler Tomography (ODT) is a noninvasive 3-D optical interferometric imaging technique that measures static and dynamic structures in a sample. To obtain the dynamic structure, e.g. blood flowing in tissue, a velocity estimation algorithm detects the Doppler shift in the received interference fringe data with respect to the carrier frequency. Previous velocity estimation algorithms use...

We describe the concept of Doppler asymmetric spatial heterodyne spectroscopy (DASH) and present a laboratory Doppler-shift measurement using an infrared laser line. DASH is a modification of spatial heterodyne spectroscopy optimized for high precision, high accuracy Doppler-shift measurements of atmospheric emission lines either from the ground or a satellite. We discuss DASH design considerat...