Andreev Reflection without Fermi surface alignment in High Tc_{c}-Topological heterostructures

We address the controversy over the proximity effect between topological materials and high T$_{c}$ superconductors. Junctions are produced between Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta}$ and materials with different Fermi surfaces (Bi$_{2}$Te$_{3}$ \& graphite). Both cases reveal tunneling spectra consistent with Andreev reflection. This is confirmed by magnetic field that shifts features via the Doppler effect. This is modeled with a single parameter that accounts for tunneling into a screening supercurrent. Thus the tunneling involves Cooper pairs crossing the heterostructure, showing the Fermi surface mis-match does not hinder the ability to form transparent interfaces, which is accounted for by the extended Brillouin zone and different lattice symmetries

Requirements specification and architecture design for internet-based control

The Internet is playing an important role not only in information retrieving, but also in industrial processes manipulation. This paper describes an approach to writing requirements specification for Internet-based control systems and to deriving architecture for this new type of control systems according to the requirements specification. Specification is described in terms of a functional model and then extended into information architecture. Distinct from the functional model, the information architecture gives an indication to the architecture of the Internet-based control systems. An integrated-distributed architecture has been derived from the functional model and the information architecture as a case study

Remarks on Hawking radiation as tunneling from the BTZ black holes

Hawking radiation viewed as a semiclassical tunneling process from the event horizon of the (2 + 1)-dimensional rotating BTZ black hole is carefully reexamined by taking into account not only the energy conservation but also the conservation of angular momentum when the effect of the emitted particle's self-gravitation is incorporated. In contrast to previous analysis of this issue in the literature, our result obtained here fits well to the Kraus-Parikh-Wilczek's universal conclusion without any modification to the Bekenstein-Hawking area-entropy formulae of the BTZ black hole.Comment: 12pages, no figure, use JHEP3.cls. Version better than published one in JHE

Evidence for a New Excitation at the Interface Between a High-Tc Superconductor and a Topological Insulator

High-temperature superconductors exhibit a wide variety of novel excitations. If contacted with a topological insulator, the lifting of spin rotation symmetry in the surface states can lead to the emergence of unconventional superconductivity and novel particles. In pursuit of this possibility, we fabricated high critical-temperature (Tc ~ 85 K) superconductor/topological insulator (Bi2Sr2CaCu2O8+delta/Bi2Te2Se) junctions. Below 75 K, a zero-bias conductance peak (ZBCP) emerges in the differential conductance spectra of this junction. The magnitude of the ZBCP is suppressed at the same rate for magnetic fields applied parallel or perpendicular to the junction. Furthermore, it can still be observed and does not split up to at least 8.5 T. The temperature and magnetic field dependence of the excitation we observe appears to fall outside the known paradigms for a ZBCP

Atomic-scale visualization of quasiparticle interference on a type-II Weyl semimetal surface

We combine quasiparticle interference simulation (theory) and atomic resolution scanning tunneling spectro-microscopy (experiment) to visualize the interference patterns on a type-II Weyl semimetal Mo$_{x}$W$_{1-x}$Te$_2$ for the first time. Our simulation based on first-principles band topology theoretically reveals the surface electron scattering behavior. We identify the topological Fermi arc states and reveal the scattering properties of the surface states in Mo$_{0.66}$W$_{0.34}$Te$_2$. In addition, our result reveals an experimental signature of the topology via the interconnectivity of bulk and surface states, which is essential for understanding the unusual nature of this material.Comment: To appear in Phys. Rev. Let

Ground-based remote sensing cloud detection using dual pyramid network and encoder–decoder constraint

Many methods for ground-based remote sensing cloud detection learn representation features using the encoder–decoder structure. However, they only consider the information from single scale, which leads to incomplete feature extraction. In this article, we propose a novel deep network named dual pyramid network (DPNet) for ground-based remote sensing cloud detection, which possesses an encoder–decoder structure with dual pyramid pooling module (DPPM). Specifically, we process the feature maps of different scales in the encoder through dual pyramid pooling. Then, we fuse the outputs of the dual pyramid pooling in the same pyramid level using the attention fusion. Furthermore, we propose the encoder–decoder constraint (EDC) to relieve information loss in the process of encoding and decoding. It constrains the values and the gradients of probability maps from the encoder and the decoder to be consistent. Since the number of cloud images in the publicly available databases for ground-based remote sensing cloud detection is limited, we release the TJNU Large-scale Cloud Detection Database (TLCDD) that is the largest database in this field. We conduct a series of experiments on TLCDD, and the experimental results verify the effectiveness of the proposed method

Mirror protected Dirac fermions on a Weyl semimetal NbP surface

The first Weyl semimetal was recently discovered in the NbP class of compounds. Although the topology of these novel materials has been identified, the surface properties are not yet fully understood. By means of scanning tunneling spectroscopy, we find that NbPs (001) surface hosts a pair of Dirac cones protected by mirror symmetry. Through our high resolution spectroscopic measurements, we resolve the quantum interference patterns arising from these novel Dirac fermions, and reveal their electronic structure, including the linear dispersions. Our data, in agreement with our theoretical calculations, uncover further interesting features of the Weyl semimetal NbPs already exotic surface. Moreover, we discuss the similarities and distinctions between the Dirac fermions here and those in topological crystalline insulators in terms of symmetry protection and topology