3D quantum Hall effect of Fermi arcs in topological semimetals

The quantum Hall effect is usually observed in 2D systems. We show that the Fermi arcs can give rise to a distinctive 3D quantum Hall effect in topological semimetals. Because of the topological constraint, the Fermi arc at a single surface has an open Fermi surface, which cannot host the quantum Hall effect. Via a "wormhole" tunneling assisted by the Weyl nodes, the Fermi arcs at opposite surfaces can form a complete Fermi loop and support the quantum Hall effect. The edge states of the Fermi arcs show a unique 3D distribution, giving an example of (d-2)-dimensional boundary states. This is distinctly different from the surface-state quantum Hall effect from a single surface of topological insulator. As the Fermi energy sweeps through the Weyl nodes, the sheet Hall conductivity evolves from the 1/B dependence to quantized plateaus at the Weyl nodes. This behavior can be realized by tuning gate voltages in a slab of topological semimetal, such as the TaAs family, Cd$_3$As$_2$, or Na$_3$Bi. This work will be instructive not only for searching transport signatures of the Fermi arcs but also for exploring novel electron gases in other topological phases of matter.Comment: 5 pages, 3 figure

Renormalization-group improved predictions for Higgs boson production at large pTp_T

We study the next-to-next-to-leading logarithmic order resummation for the large $p_T$ Higgs boson production at the LHC in the framework of soft-collinear effective theory. We find that the resummation effects reduce the scale uncertainty significantly and decrease the QCD NLO results by about $11\%$ in the large $p_T$ region. The finite top quark mass effects and the effects of the NNLO singular terms are also discussed.Comment: 31 pages, 17 figures, version published in Phys.Rev.

Effects of e-Commerce Websites’ Auditory Features on Consumers’ Appreciation for Innovative Products

It is has been established that sensory interactions, including sight, hearing, smell, taste and touch, can affect consumers’ consumption decisions. While various sensory interactions are devised in the offline context, e-commerce has to rely primarily on vision and hearing due to its inability to access other sensory. Previous IS literature has documented the substantial effects of various visual features. However, very few studies have examined auditory features. Drawing on the recent observation that medium noises enhance people’s abstractive thinking and creativity, this study tries to investigate this topic from a novel perspective that ambient sounds can promote users’ appreciation of innovative products when shopping online. The preliminary results of a lab experiment show that medium noise or music can improve participants’ likelihood of buying innovative products over traditional products, and noise brings other negative effects (e.g. bad mood), while music do not. Theoretical and practical contributions are discussed