Testing What’s at Stake: Defending Stakes Effects for Testimony

This paper investigates whether practical interests affect knowledge attributions in cases of testimony. It is argued that stakes impact testimonial knowledge attributions by increasing or decreasing the requirements for hearers to trust speakers and thereby gain the epistemic right to acquire knowledge via testimony. Standard, i.e. invariantist, reductionism and non-reductionism fail to provide a plausible account of testimony that is stakes sensitive, while non- invariantist versions of both traditional accounts can remedy this deficiency. Support for this conceptual analysis of stakes is found through a review of the experimental philosophy literature on stakes effects on knowledge attribution. Finally, a diagnosis is offered for what is needed to provide a more robust defense of the paper’s primary claims in terms of future experimental study

Unconventional Superconductivity near Inhomogeneities

In der Arbeit wurde der Einfluss von Inhomogenitaeten in verschiedenen Systeme unkonventioneller Supraleiter untersucht. Mit der quasiklassischen Theorie der Supraleitung wird die spezifische Waerme in Sr2RuO4 fuer verschiedene Modelle betrachtet. Im weiteren werden Transporteigenschaften von Kontakten zwischen Hochtemperatur-Supraleitern und der Einfluss von Verunreinigungen untersucht. Im letzten Teil wird eine S-Matrix zur Beschreibung von Supraleiter-Ferromagnet-Heterostrukturen hergeleitet

Broadening of Andreev-Bound States in d_{x^2-y^2} superconductors

We investigate the broadening of the bound states at an interface of an unconventional superconductor by bulk impurity scattering. We use the quasiclassical theory and include impurity scattering in the Born and in the unitarity limit. The broadening of bound states due to unitary scatterers is shown to be substantially weaker than in the Born limit. We study various model geometries and calculate the temperature dependence of the Josephson critical current in the presence of these impurity-broadened bound states.Comment: 6 page including 7 figures, submitted to Phys. Rev.

Emotional Intelligence as an Intellectual Virtue: Theoretical Analysis and Empirical Assessment

Virtue theory has long recognized the significance of emotion for cognition, yet little philosophical research has been dedicated to identifying an intellectual virtue related to emotion. Applying recent work in virtue epistemology reveals emotional intelligence (EI) to be an intellectual virtue, as analysis demonstrates EI’s ability to enhance cognition. High EI persons better attend to epistemically-significant features of the environment, which could explain the significance of stakes for knowledge attribution. While testing did not confirm higher EI with stakes sensitivity (the hypothesis), study methods, including stakes vignettes, inadvertently caused the hypothesis to be disconfirmed

Subharmonic gap structure in d-wave superconductors

We present a self-consistent theory of current-voltage characteristics of d-wave/d-wave contacts at arbitrary transparency. In particular, we address the open problem of the observation of subharmonic gap structure (SGS) in cuprate junctions. Our analysis shows that: (i) the SGS is possible in d-wave superconductors, (ii) the existence of bound states within the gap results in an even-odd effect in the SGS, (iii) elastic scattering mechanisms, like impurities or surface roughness, may suppress the SGS, and (iv) in the presence of a magnetic field the Doppler shift of the Andreev bound states leads to a very peculiar splitting of the SGS, which is an unambiguous fingerprint of d-wave superconductivity.Comment: Revtex4, 4 pages, 5 figure

Interplay between single-particle and two-particle tunneling in normal metal-d-wave superconductor junctions probed by shot noise

We discuss how life-time broadening of quasiparticle states influences single- and two-particle current transport through zero-energy states at normal metal/d-wave superconductor junctions. We distinguish between intrinsic broadening (imaginary part $\eta$ of the energy), which couples the bound states with the superconducting reservoir, and broadening due to leakage through the junction barrier, which couples the bound states with the normal metal reservoir. We show that shot noise is highly sensitive to the mechanism of broadening, while the conductance is not. In the limit of small but finite intrinsic broadening, compared to the junction transparency $D$, $\eta/\Delta_0\ll D$, the low-voltage shot noise at zero frequency and zero temperature becomes proportional to the magnitude $\eta$ of intrinsic broadening ($\Delta_0$ is the maximum d-wave gap).Comment: 6 pages, 4 figures; presented at the SDP2001 conference in Toky

Two regimes for effects of surface disorder on the zero-bias conductance peak of tunnel junctions involving d-wave superconductors

Impurity-induced quasiparticle bound states on a pair-breaking surface of a d-wave superconductor are theoretically described, taking into account hybridization of impurity- and surface-induced Andreev states. Further a theory for effects of surface disorder (of thin impurity surface layer) on the low-bias conductance of tunnel junctions is developed. We find a threshold $n_c$ for surface impurity concentration $n_S$, which separates the two regimes for surface impurity effects on the zero-bias conductance peak (ZBCP). Below the threshold, surface impurities do not broaden the ZBCP, but effectively reduce its weight and generate impurity bands. For low $n_S$ impurity bands can be, in principle, resolved experimentally, being centered at energies of bound states induced by an isolated impurity on the surface. For larger $n_S$ impurity bands are distorted, move to lower energies and, beginning with the threshold concentration $n_S=n_c$, become centered at zero energy. With increasing $n_S$ above the threshold, the ZBCP is quickly destroyed in the case of strong scatterers, while it is gradually suppressed and broaden in the presence of weak impurity potentials. More realistic cases, taking into account additional broadening, not related to the surface disorder, are also considered.Comment: 9 pages, 7 figure

Shot noise in normal metal-d-wave superconducting junctions

We present theoretical calculations and predictions for the shot noise in voltage biased junctions of $d_{x^2-y^2}$ superconductors and normal metal counter-electrodes. In the clean limit for the d-wave superconductor the shot noise vanishes at zero voltage because of resonant Andreev reflection by zero-energy surface bound states. We examine the sensitivity of this resonance to impurity scattering. We report theoretical results for the magnetic field dependence of the shot noise, as well the fingerprints of subdominant $s$- and $d_{xy}$ pairing channels.Comment: 15 pages, 8 figures and 3 tables embedde