Knight Shift in the FFLO State of a Two-Dimensional D-Wave Superconductor

We report on the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state in two-dimensional d-wave superconductors with magnetic field parallel to the superconducting planes. This state occurs at high magnetic field near the Pauli-Clogston limit and is a consequence of the competition between the pair condensation and Zeeman energy. We use the quasiclassical theory to self-consistently compute the spatially nonuniform order parameter. Our self-consistent calculations show that the FFLO state of a d-wave order parameter breaks translational symmetry along preferred directions. The orientation of the nodes in real space is pinned by the nodes of the basis function in momentum space. Here, we present results for the Knight shift and discuss the implications for recent nuclear magnetic resonance measurements on CeCoIn5.Comment: 2 pages, 3 figures: LT-24 Conference, Orlando, Aug. 2005; to appear in AIP Conference Proceeding

Pauli-Limited Superconductivity with Classical Magnetic Fluctuations

We examine the effect of classical magnetic fluctuations on the phase diagram of paramagneticallylimited two-dimensional superconductors under a Zeeman magnetic field. We derive the free energy expansion in powers of the superconducting order parameter and analyze the character of the normalsuperconducting transition. While the transition is of the second order for all temperatures in the absence of magnetic fluctuations, we find that proximity to magnetism drives both the transition into the uniform state and that into the modulated (Fulde-Ferrell-Larkin-Ovchinnikov, FFLO) state to first order at intermediate temperatures. We compute the thermodynamic signatures of the normal-superconducting transition along the upper critical field.Comment: 16 pages, 9 figure

Role of the fermi-surface anisotropy in angle-dependent magnetic-field oscillations for identifying the energy-gap anisotropy of A yFe 2Se 2 superconductors

We present a numerical study of the field-angle resolved oscillations of the thermal conductivity and specific heat under a rotated magnetic field in the A yFe 2-xSe 2 [A=K, Rb, Cs, (Tl, K)] superconductors, using realistic two-band Fermi surface parametrization. Our key finding is that even for isotropic pairing on an anisotropic Fermi surface, the thermodynamic quantities exhibit substantial oscillatory behavior in the superconducting state, even much below the upper critical field. Furthermore, in multiband systems the competition of anisotropies between two Fermi surfaces can cause a double sign reversal of oscillations as a function of temperature, irrespective of gap anisotropy. Our findings put severe constraints on simple interpretations of field-angle resolved measurements widely used to identify the angular structure of the superconducting gap. © 2012 American Physical Society

Fermi-liquid effects in the Fulde-Ferrell-Larkin-Ovchinnikov state of two-dimensional d-wave superconductors

We study the effects of Fermi-liquid interactions on quasi-two-dimensional d-wave superconductors in a magnetic field. The phase diagram of the superconducting state, including the periodic Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state in high magnetic fields, is discussed for different strengths of quasiparticle many-body interactions within Landau's theory of Fermi liquids. Decreasing the Fermi-liquid parameter $F_0^a$ causes the magnetic spin susceptibility to increase, which in turn leads to a reduction of the FFLO phase. It is shown that a negative $F_0^a$ results in a first-order phase transition from the normal to the uniform superconducting state in a finite temperature interval. Finally, we discuss the thermodynamic implications of a first-order phase transition for CeCoIn$_5$.Comment: published version; removed direct comparison with experiment for the upper critical field, as required by the referee

Narcissism and the strategic pursuit of short-term mating : universal links across 11 world regions of the International Sexuality Description Project-2.

Previous studies have documented links between sub-clinical narcissism and the active pursuit of short-term mating strategies (e.g., unrestricted sociosexuality, marital infidelity, mate poaching). Nearly all of these investigations have relied solely on samples from Western cultures. In the current study, responses from a cross-cultural survey of 30,470 people across 53 nations spanning 11 world regions (North America, Central/South America, Northern Europe, Western Europe, Eastern Europe, Southern Europe, Middle East, Africa, Oceania, Southeast Asia, and East Asia) were used to evaluate whether narcissism (as measured by the Narcissistic Personality Inventory; NPI) was universally associated with short-term mating. Results revealed narcissism scores (including two broad factors and seven traditional facets as measured by the NPI) were functionally equivalent across cultures, reliably associating with key sexual outcomes (e.g., more active pursuit of short-term mating, intimate partner violence, and sexual aggression) and sex-related personality traits (e.g., higher extraversion and openness to experience). Whereas some features of personality (e.g., subjective well-being) were universally associated with socially adaptive facets of Narcissism (e.g., self-sufficiency), most indicators of short-term mating (e.g., unrestricted sociosexuality and marital infidelity) were universally associated with the socially maladaptive facets of narcissism (e.g., exploitativeness). Discussion addresses limitations of these cross-culturally universal findings and presents suggestions for future research into revealing the precise psychological features of narcissism that facilitate the strategic pursuit of short-term mating