Unconventional superconductors under rotating magnetic field II: thermal transport

We present a microscopic approach to the calculations of thermal conductivity in unconventional superconductors for a wide range of temperatures and magnetic fields. Our work employs the non-equilibrium Keldysh formulation of the quasiclassical theory. We solve the transport equations using a variation of the Brandt-Pesch-Tewordt (BPT) method, that accounts for the quasiparticle scattering on vortices. We focus on the dependence of the thermal conductivity on the direction of the field with the respect to the nodes of the order parameter, and discuss it in the context of experiments aiming to determine the shape of the gap from such anisotropy measurements. We consider quasi-two dimensional Fermi surfaces with vertical line nodes and use our analysis to establish the location of gap nodes in heavy fermion CeCoIn$_5$ and organic superconductor $\kappa$-(BEDT-TTF)$_2$Cu(NCS)$_2$.Comment: 17 pages, 13 figure

Model calculation of orientational effect of deformed aerogel on the order parameter of superfluid 3He

Theory of Rainer and Vuorio of small objects in superfluid ^3He is applied for calculation of the average orientational effect of a deformed aerogel on the order parameter of 3He. The minimum deformation which stabilizes the ordered state is evaluated both for specular and diffusive scattering of quasiparticles by the threads of aerogel.Comment: Contribution to QFS 2007, 6 pages, 1 figur

A solution NMR approach to determine the chemical structures of carbohydrates using the hydroxyl groups as starting points

An efficient NMR approach is described for determining the chemical structures of the monosaccharide glucose and four disaccharides, namely, nigerose, gentiobiose, leucrose and isomaltulose. This approach uses the 1H resonances of the −OH groups, which are observable in the NMR spectrum of a supercooled aqueous solution, as the starting point for further analysis. The 2D-NMR technique, HSQC-TOCSY, is then applied to fully define the covalent structure (i.e., the topological relationship between C–C, C–H, and O–H bonds) that must be established for a novel carbohydrate before proceeding to further conformational studies. This process also leads to complete assignment of all 1H and 13C resonances. The approach is exemplified by analyzing the monosaccharide glucose, which is treated as if it were an “unknown”, and also by fully assigning all the NMR resonances for the four disaccharides that contain glucose. It is proposed that this technique should be equally applicable to the determination of chemical structures for larger carbohydrates of unknown composition, including those that are only available in limited quantities from biological studies. The advantages of commencing the structure elucidation of a carbohydrate at the −OH groups are discussed with reference to the now well-established 2D-/3D-NMR strategy for investigation of peptides/proteins, which employs the −NH resonances as the starting point

From Color Fields to Quark Gluon Plasma

We discuss a model for the energy distribution and the early space-time evolution of a heavy ion collision. We estimate the gluon field generated in the wake of hard processes and through primordial fluctuations of the color charges in the nuclei. Without specifying the dynamical mechanism of thermalization we calculate the energy momentum tensor of the following plasma phase. The results of this model can be used as initial conditions for a further hydrodynamic evolution.Comment: Contribution to Quark Matter 2005; 4 pages, 4 figure

Non-axisymmetric Magnetorotational Instabilities in Cylindrical Taylor-Couette Flow

We study the stability of cylindrical Taylor-Couette flow in the presence of azimuthal magnetic fields, and show that one obtains non-axisymmetric magnetorotational instabilities, having azimuthal wavenumber m=1. For Omega_o/Omega_i only slightly greater than the Rayleigh value (r_i/r_o)^2, the critical Reynolds and Hartmann numbers are Re_c ~ 10^3 and Ha_c ~ 10^2, independent of the magnetic Prandtl number Pm. These values are sufficiently small that it should be possible to obtain these instabilities in the PROMISE experimental facility.Comment: final version as accepted by Phys Rev Let

Early Time Evolution of High Energy Heavy Ion Collisions

We solve the Yang-Mills equations in the framework of the McLerran-Venugopalan model for small times tau after a collision of two nuclei. An analytic expansion around tau=0 leads to explicit results for the field strength and the energy momentum tensor of the gluon field at early times. We then discuss constraints for the energy density, pressure and flow of the plasma phase that emerges after thermalization of the gluon field.Comment: 4 pages, 1 figure; contribution to Quark Matter 2006; submitted to J. Phys.

Robust superfluid phases of 3He in aerogel

Within a phenomenological approach possible forms of the order parameter of the superfluid phases of 3He in a vicinity of the transition temperature are discussed. Effect of aerogel is described by a random tensor field interacting with the orbital part of the order parameter. With respect to their interaction with the random tensor field a group of "robust" order parameters which can maintain long-range order in a presence of the random field is specified. Robust order parameters, corresponding to Equal Spin Pairing (ESP) states are found and proposed as candidates for the observed A-like superfluid phase of liquid 3He in aerogel.Comment: 5 pages, prepared for QFS 200

Combinatorial and Chemotopic Odorant Coding in the Zebrafish Olfactory Bulb Visualized by Optical Imaging

AbstractOdors are thought to be represented by a distributed code across the glomerular modules in the olfactory bulb (OB). Here, we optically imaged presynaptic activity in glomerular modules of the zebrafish OB induced by a class of natural odorants (amino acids [AAs]) after labeling of primary afferents with a calcium-sensitive dye. AAs induce complex combinatorial patterns of active glomerular modules that are unique for different stimuli and concentrations. Quantitative analysis shows that defined molecular features of stimuli are correlated with activity in spatially confined groups of glomerular modules. These results provide direct evidence that identity and concentration of odorants are encoded by glomerular activity patterns and reveal a coarse chemotopic organization of the array of glomerular modules