Double Andreev Reflections in Type-II Weyl Semimetal-Superconductor Junctions

We study the Andreev reflections (ARs) at the interface of the type-II Weyl semimetal-superconductor junctions and find double ARs when the superconductor is put in the Weyl semimetal band tilting direction, which is similar to the double reflections of light in anisotropic crystals. The directions of the double (retro and specular) ARs are symmetric about the normal due to the hyperboloidal Fermi surface near the Weyl nodes, but with different AR amplitudes depending on the direction and energy of the incident electron. When the normal direction of the Weyl semimetal-superconductor interface is changed from parallel to perpendicular with the tilt direction, the double ARs gradually evolve from one retro-AR and one specular AR, passing through double retro-ARs, one specular AR and one retro-AR, into one retro AR and one normal reflection, resulting in an anisotropic conductance which can be observed in experiments.Comment: 12 pages, 7 figure

A Labelled Sequent Calculus for BBI: Proof Theory and Proof Search

We present a labelled sequent calculus for Boolean BI, a classical variant of O'Hearn and Pym's logic of Bunched Implication. The calculus is simple, sound, complete, and enjoys cut-elimination. We show that all the structural rules in our proof system, including those rules that manipulate labels, can be localised around applications of certain logical rules, thereby localising the handling of these rules in proof search. Based on this, we demonstrate a free variable calculus that deals with the structural rules lazily in a constraint system. A heuristic method to solve the constraints is proposed in the end, with some experimental results

Crossed Andreev effects in two-dimensional quantum Hall systems

We study the crossed Andreev effects in two-dimensional conductor/superconductor hybrid systems under a perpendicular magnetic field. Both a graphene/superconductor hybrid system and an electron gas/superconductor one are considered. It is shown that an exclusive crossed Andreev reflection, with other Andreev reflections being completely suppressed, is obtained in a high magnetic field because of the chiral edge states in the quantum Hall regime. Importantly, the exclusive crossed Andreev reflection not only holds for a wide range of system parameters, e.g., the size of system, the width of central superconductor, and the quality of coupling between the graphene and the superconductor, but also is very robust against disorder. When the applied bias is within the superconductor gap, a robust Cooper-pair splitting process with high-efficiency can be realized in this system.Comment: 10 pages, 10 figure

New Bounds on the Minimum Calls of Failure-Tolerant Gossiping

Gossiping is an extensively investigated information dissemination process. In gossiping, every vertex holds a message which has to be transmitted to all other vertices. This paper deals with k-failure tolerant gossiping, which investigates the minimum number of transmissions (calls) required by the communication process, provided that at most k transmissions may fail. We show new bounds for the number of transmissions, which are better than the previous results if k is sufficiently large. In addition, some examples of k-failure tolerant gossiping with fewer transmissions are shown for small graphs

Consumer use intention of online financial products: the Yuebao example

Drawing on a valence framework and innovation diffusion theory, this study examines Yuebao deployment to model consumers' intention to use financial products offered online. We collect data via an online survey among a young age bracket and use a VisualPLS graphic interface to test our model. The results indicate that first, compatibility and advantages in relative utility significantly enhance consumers' use intentions and that ease of use has an indirect influence. Second, the negative utility of perceived risk no longer significantly affects intention to use. This mainly lies in consumers' perceived risk focused on the security of online financial products, which has become a part of all online transactions. Third, trust indirectly affects intention to use by influencing utility