arXiv subjects

Tao Xie

Publications and source records attributed to Tao Xie.

166 records · Page 10Linked to original sources

arXiv2016

Electronic specific heat in BaFe$_{2-x}$Ni$_x$As$_2$

We have systematically studied the low-temperature specific heat of the BaFe$_{2-x}$Ni$_x$As$_2$ single crystals covering the whole superconducting dome. Using the nonsuperconducting heavily overdoped x = 0.3 sample as a reference for the phonon contribution to the specific heat, we find that the normal-state electronic specific heats in the superconducting samples may have a nonlinear temperature dependence, which challenges previous results in the electron-doped Ba-122 iron-based superconductors. A model based on the presence of ferromagnetic spin fluctuations may explain the data between x = 0.1 and x = 0.15, suggesting the important role of Fermi-surface topology in understanding the normal-state electronic states.

cond-mat.supr-con↗

arXiv2015

Electron-doping dependence of the anisotropic superconductivity in BaFe$_{2-x}$Ni$_{x}$As$_2$

The upper critical field ($H_{c2}$) in superconducting BaFe$_{2-x}$Ni$_{x}$As$_2$ single crystals has been determined by magnetotransport measurements down to 0.6 K over the whole superconducting dome with $0.065 \leqslant x \leqslant 0.22$, both for the inter-plane ($H \parallel c$, $H_{c2}^{c}$) and in-plane ($H \parallel ab$, $H_{c2}^{ab}$) field directions in static magnetic fields up to 16 T and pulsed magnetic fields up to 60 T. The temperature dependence of $H_{c2}^{ab}$ follows the Werthamer-Helfand-Hohenberg (WHH) model incorporating orbital and spin paramagnetic effects, while $H_{c2}^{c}(T)$ can only be described by the effective two-band model with unbalanced diffusivity. The anisotropy of the upper critical fields, $γ(T)=H_{c2}^{ab}/H_{c2}^{c}$ monotonically increases with increasing temperature for all dopings, and its zero-temperature limit, $γ(0)$, has an asymmetric doping dependence with a significant enhancement in the overdoped regime, where the optimally doped compound has the most isotropic superconductivity. Our results suggest that the anisotropy in the superconductivity of iron pnictides is determined by the topology of the Fermi surfaces together with the doping-induced impurity scattering.

cond-mat.supr-con↗

arXiv2013

Want a Good Answer? Ask a Good Question First!

Community Question Answering (CQA) websites have become valuable repositories which host a massive volume of human knowledge. To maximize the utility of such knowledge, it is essential to evaluate the quality of an existing question or answer, especially soon after it is posted on the CQA website. In this paper, we study the problem of inferring the quality of questions and answers through a case study of a software CQA (Stack Overflow). Our key finding is that the quality of an answer is strongly positively correlated with that of its question. Armed with this observation, we propose a family of algorithms to jointly predict the quality of questions and answers, for both quantifying numerical quality scores and differentiating the high-quality questions/answers from those of low quality. We conduct extensive experimental evaluations to demonstrate the effectiveness and efficiency of our methods.

cs.DB↗

arXiv2013

A Preliminary Field Study of Game Programming on Mobile Devices

TouchDevelop is a new programming environment that allows users to create applications on mobile devices. Applications created with TouchDevelop have continued to grow in popularity since TouchDevelop was first released to public in 2011. This paper presents a field study of 31,699 applications, focusing on different characteristics between 539 game scripts and all other non-game applications, as well as what make some game applications more popular than others to users. The study provides a list of findings on characteristics of game scripts and also implications for improving end-user programming of game applications.

cs.SE↗