Dark polariton-solitons in semiconductor microcavities

We report the existence, symmetry breaking and other instabilities of dark polariton-solitons in semiconductor microcavities operating in the strong coupling regime. These half-light half-matter solitons are potential candidates for applications in all-optical signal processing. Their excitation time and required pump powers are a few orders of magnitude less than those of their weakly coupled light-only counterparts.Comment: submitted to PR

Frequency selection by soliton excitation in nondegenerate intracavity downconversion

We show that soliton excitation in intracavity downconversion naturally selects a strictly defined frequency difference between the signal and idler fields. In particular, this phenomenon implies that if the signal has smaller losses than the idler then its frequency is pulled away from the cavity resonance and the idler frequency is pulled towards the resonance and {\em vice versa}. The frequency selection is shown to be closely linked with the relative energy balance between the idler and signal fields.Comment: 5 pages, 3 figures. To appear in Phys Rev Let

Modulational instability of solitary waves in non-degenerate three-wave mixing: The role of phase symmetries

We show how the analytical approach of Zakharov and Rubenchik [Sov. Phys. JETP {\bf 38}, 494 (1974)] to modulational instability (MI) of solitary waves in the nonlinear Schr\"oedinger equation (NLS) can be generalised for models with two phase symmetries. MI of three-wave parametric spatial solitons due to group velocity dispersion (GVD) is investigated as a typical example of such models. We reveal a new branch of neck instability, which dominates the usual snake type MI found for normal GVD. The resultant nonlinear evolution is thereby qualitatively different from cases with only a single phase symmetry.Comment: 4 pages with figure

Theory of radiation trapping by the accelerating solitons in optical fibers

We present a theory describing trapping of the normally dispersive radiation by the Raman solitons in optical fibers. Frequency of the radiation component is continuously blue shifting, while the soliton is red shifting. Underlying physics of the trapping effect is in the existence of the inertial gravity-like force acting on light in the accelerating frame of reference. We present analytical calculations of the rate of the opposing frequency shifts of the soliton and trapped radiation and find it to be greater than the rate of the red shift of the bare Raman soliton. Our findings are essential for understanding of the continuous shift of the high frequency edge of the supercontinuum spectra generated in photonic crystal fibers towards higher frequencies.Comment: Several misprints in text and formulas corrected. 10 pages, 9 figures, submitted to Phys. Rev.

Critical sound attenuation in a diluted Ising system

The field-theoretic description of dynamical critical effects of the influence of disorder on acoustic anomalies near the temperature of the second-order phase transition is considered for three-dimensional Ising-like systems. Calculations of the sound attenuation in pure and dilute Ising-like systems near the critical point are presented. The dynamical scaling function for the critical attenuation coefficient is calculated. The influence of quenched disorder on the asymptotic behaviour of the critical ultrasonic anomalies is discussed.Comment: 12 RevTeX pages, 4 figure

Manipulations with early mouse embryos for generation of genetically modified animals

Recently, genome-editing technologies have  become more efficient and accessible. The discovery of nucleases for directional genome editing (CRISPR/Cas9, TALEN, ZFNs) significantly accelerated and simplified the production of mice with targeted gene editing in the genome. Until last time, the CRISPR/Cas9 system noticeably simplified the preparation of knockout or transgenic mice. CRISPR/Cas9 technology was successfully applied for gene knockout and knock-in, generation of large deletions or directed insertions in targeted genome regions in embryonic stem cells (ESCs).When injected into blastocysts, such  modified ESCs are able to generate chimeras producing gametes with an identical genotype with ESC. Thus, it can identify animals with modified genomes. More recently, CRISPR/Cas9 technology was successfully applied to mouse zygotes and the birth of genetic modified mice was observed, i. e., the time required for generating genome-modified animals decreased significantly. The CRISPR/Cas9 system allows making gene knockout, large deletions or directed insertions into the target region of the genome by cytoplasm or pronuclear microinjection into zygotes. In addition, this is faster and simpler than similar work with mouse ESCs. Meanwhile, methods of manipulation with early embryos and their transplantation to surrogate mothers may be somewhat tricky. Therefore, it is important to use modern technologies for directional genome editing and perfect mastery in the embryological technics. In this article, we describe the protocols of microinjection into the pronucleus or cytoplasm of zygotes and injection of embryonic stem cells into the blastocyst cavity. We also describe embryological methods, such as superovulation, preparation of early stage  embryos,  surgical operation, production of foster mice. In addition, we describe the assembly and necessary components for the isoflurane anesthetic apparatus and isoflurane anesthesia