Neural correlates of emotion word processing: the complex relation between emotional valence and arousal

Poster Session 1: no. 2The Conference's website is located at http://events.unitn.it/en/psb2010Emotion is characterised by a two-dimensional structure: valence describes the extent to which an emotion is positive or negative, whereas arousal refers to the intensity of an emotion, how exciting or calming it is. Emotional content of verbal material influences cognitive processing during lexical decision, naming, emotional Stroop task and many others. Converging findings showed that emotionally valenced words (positive or negative) are processed faster than neutral words, as shown by reaction time and ERP measures, suggesting a prioritisation of emotional …published_or_final_versio

Field-induced suppression of the heavy-fermion state in YbRh_2Si_2

We report DC magnetization measurements on YbRh_2Si_2 at temperatures down to 0.04K, magnetic fields B<11.5T and under hydrostatic pressure P<1.3GPa. At ambient pressure a kink at B*=9.9T indicates a new type of field-induced transition from an itinerant to a localized 4f-state. This transition is different from the metamagnetic transition observed in other heavy fermion compounds, as here ferromagnetic rather than antiferromagnetic correlations dominate below B*. Hydrostatic pressure experiments reveal a clear correspondence of B* to the characteristic spin fluctuation temperature determined from specific heat

Low-temperature thermopower study of YbRh2Si2

The heavy-fermion compound YbRh2Si2 exhibits an antiferromagnetic (AFM) phase transition at an extremely low temperature of TN = 70 mK. Upon applying a tiny magnetic field of Bc = 60 mT the AFM ordering is suppressed and the system is driven toward a field-induced quantum critical point (QCP). Here, we present low-temperature thermopower S(T) measurements of high-quality YbRh2Si2 single crystals down to 30 mK. S(T) is found negative with comparably large values in the paramagnetic state. In zero field no Landau-Fermi-liquid (LFL) like behavior is observed within the magnetically ordered phase. However, a sign change from negative to positive appears at lowest temperatures on the magnetic side of the QCP. For higher fields B > Bc a linear extrapolation of S to zero clearly evidences the recovery of LFL regime. The crossover temperature is sharply determined and coincides perfectly with the one derived from resistivity and specific heat investigations.Comment: LT25 conference proceedings in Journal of Physics: Conference Serie

Observation of an optical non-Fermi-liquid behavior in the heavy fermion state of YbRh2_{2}Si2_{2}

We report far-infrared optical properties of YbRh$_{2}$Si$_{2}$ for photon energies down to 2 meV and temperatures 0.4 -- 300 K. In the coherent heavy quasiparticle state, a linear dependence of the low-energy scattering rate on both temperature and photon energy was found. We relate this distinct dynamical behavior different from that of Fermi liquid materials to the non-Fermi liquid nature of YbRh$_{2}$Si$_{2}$ which is due to its close vicinity to an antiferromagnetic quantum critical point.Comment: 5 pages, 4 figures. submitte

Spin dynamics of YbRh2Si2Yb Rh_2 Si_2 observed by Electron Spin Resonance

Below the Kondo temperature $T_{\rm K}$ electron spin resonance (ESR) usually is not observable from the Kondo-ion itself because the characteristic spin fluctuation energy results in a huge width of the ESR line. The heavy fermion metal YbRh$_{2}$Si$_{2}$ seems to be an exceptional case where definite ESR spectra show characteristic properties of the Kondo-ion Yb$^{3+}$ well \textit{below} $T_{\rm K}$. We found that the spin dynamics of YbRh$_{2}$Si$_{2}$, as determined by its ESR relaxation, is spatially characterized by an anisotropy of the zero temperature residual relaxation only.Comment: Presented at NanoRes 2004, Kazan; 4 pages, 3 Figure

The HERMES Back Drift Chambers

The tracking system of the HERMES spectrometer behind the bending magnet consists of two pairs of large planar 6-plane drift chambers. The design and performance of these chambers is described. This description comprises details on the mechanical and electronical design, information about the gas mixture used and its properties, results on alignment, calibration, resolution, and efficiencies, and a discussion of the experience gained through the first three years of operation.Comment: 21 pages, LaTex, 16 figures include

Electron spin resonance of the Kondo ion in YbRh2Si2

By means of electron spin resonance (ESR) we investigated the dynamic magnetic properties of the heavy fermion metal YbRh2Si2. This is the first observation of Yb3+-ESR in YbRh2Si 2 being also the first ESR signal of a Kondo ion in a dense Kondo lattice system. Below T = 25 K strongly anisotropic ESR spectra observed in high-quality single crystals demonstrate the existence of local Yb3+ magnetic moments even below a characteristic spin fluctuation temperature derived from thermodynamic properties. © 2003 Elsevier B.V. All rights reserved

Low Temperature Electron Spin Resonance of the Kondo Ion in a Heavy Fermion Metal: YbRh2Si2

The electron spin resonance (ESR) study on single crystals of the heavy fermion metal YbRh2Si2 was presented. The study showed non-Fermi liquid behavior related to a close antiferromagnetic quantum critical point. It was found that the spin dynamics as well as the static magnetic properties of the Yb3+ spins were consistent with the results of nuclear magnetic resonance and magnetic susceptibility