Interaction between electronic structure and strain in Bi nanolines on Si(001)

Heteroepitaxial strain can be a controlling factor in the lateral dimensions of 1-D nanostructures. Bi nanolines on Si(001) have an atomic structure which involves a large sub-surface reconstruction, resulting in a strong elastic coupling to the surrounding silicon. We present variable-bias STM and first principles electronic structure calculations of the Bi nanolines, which investigates this interaction. We show that the strain associated with the nanolines affects the atomic and electronic structure of at least two neighbouring Si dimers, and identify the mechanism behind this. We also present partial charge densities (projected by energy) for the nanoline with clean and hydrogenated surroundings and contrast it to the clean Si(001) surface.Comment: 10 pages, 3 figures, submitted to Surface Scienc

Anomalous Hall effect in non-collinear antiferromagnetic antiperovskite Mn3_{3}Ni1−x_{1-x}Cux_{x}N

We report the anomalous Hall effect (AHE) in antiperovskite Mn$_{3}$NiN with substantial doping of Cu on the Ni site (i.e. Mn$_{3}$Ni$_{1-x}$Cu$_{x}$N), which stabilizes a noncollinear antiferromagnetic (AFM) order compatible with the AHE. Observed on both sintered polycrystalline pieces and single crystalline films, the AHE does not scale with the net magnetization, contrary to the conventional ferromagnetic case. The existence of the AHE is explained through symmetry analysis based on the $\Gamma_{\rm 4g}$ AFM order in Cu doped Mn$_{3}$NiN. DFT calculations of the intrinsic contribution to the AHE reveal the non-vanishing Berry curvature in momentum space due to the noncollinear magnetic order. Combined with other attractive properties, antiperovskite Mn$_{3}$AN system offers great potential in AFM spintronics.Comment: Supplemental Materials not include

Direct Minimization Approaches on Static Problems of Membranes

Within this work, direct minimization approaches on static problems of membranes are discussed. In the first half, standard direct minimization methods are discussed. Some form-finding analyses of tension structures are also illustrated as simple direct minimization approaches. In the second half, the principle of virtual works for cables, membranes, and 3-dimensional bodies are examined and they are approximated in a common way by using Galerkin method. Finally, some examples that direct minimization approaches can solve are reported

Stress relief as the driving force for self-assembled Bi nanolines

Stress resulting from mismatch between a substrate and an adsorbed material has often been thought to be the driving force for the self-assembly of nanoscale structures. Bi nanolines self-assemble on Si(001), and are remarkable for their straightness and length -- they are often more than 400 nm long, and a kink in a nanoline has never been observed. Through electronic structure calculations, we have found an energetically favourable structure for these nanolines that agrees with our scanning tunneling microscopy and photoemission experiments; the structure has an extremely unusual subsurface structure, comprising a double core of 7-membered rings of silicon. Our proposed structure explains all the observed features of the nanolines, and shows that surface stress resulting from the mismatch between the Bi and the Si substrate are responsible for their self-assembly. This has wider implications for the controlled growth of nanostructures on semiconductor surfaces.Comment: 4 pages, 4 figures, submitted to Phys. Rev. Let

Gated Mode Superconducting Nanowire Single Photon Detectors

Single Photon Detectors (SPD) are fundamental to quantum optics and quantum information. Superconducting Nanowire SPDs (SNSPD) [1] provide high performance in terms of quantum efficiency (QE), dark count rate (DCR) and timing jitter [2], but have limited maximum count rate (MCR) when operated as a free-running mode (FM) detector [3, 4]. However, high count rates are needed for many applications like quantum computing [5] and communication [6], and laser ranging [7]. Here we report the first operation of SNSPDs in a gated mode (GM) that exploits a single photon triggered latching phenomenon to detect photons. We demonstrate operation of a large active area single element GM-SNSPD at 625MHz, one order of magnitude faster than its FM counterpart. Contrary to FM-SNSPDs, the MCR in GM can be pushed to GHz range without a compromise on the active area or QE, while reducing the DCR

Longer Fasting After Rybelsus Administration Contributes Higher Efficacy

Recent pharmacological topic for diabetes includes clinical application of Glucagon-like peptide 1 receptor agonists (GLP-1 RAs). Among them, oral semaglutide (Rybelsus) has been developed as the first oral form of GLP-1RA by useful application of sodium N-(8-[2-hydroxybenzoyl] amino) caprylate (SNAC). Semaglutide concentration in the blood was compared when fasting time period after Rybelsus administration would be 15, 30, 60 and 120 minutes. As a result, the concentration ratio after 4 hours was 1.00, 1.67, 2.60 and 3.06, respectively. Authors have experienced a diabetic case of remarkable efficacy as HbA1c -1.4% and weight -5kg, who kept 3-4 hours fasting after Rybelsus intake

The many ways of returning to the refrain in Telugu song

A refrain (abbreviated R) is a line in a song repeated after each verse, and often used as the\ua0song’s name. Returns to R are usually high points both melodically and lyrically. E.g., a verse\ua0ending "I feel upon my lips again" makes a smooth lead-in (abbreviated L) to the refrain R =\ua0"A taste of honey" (Scott/Marlow, 1962). We notate this "(I feel upon my lips again) A taste of\ua0honey", and call such patterns (lead-in)refrains or (L)R’s. The song goes R … LR … LR, where\ua0L could change verse to verse. In our examples, R and (L)R are often both full sentences. More\ua0interesting L’s are often phrases, clauses or rather than interjections. A word-prefix L can\ua0transform R.Our main contribution is to point out that (L)R patterns are a striking feature of Telugu (TEL)\ua0song, remarkably various and profuse in both old and new songs, yet little remarked in the\ua0literature as far as we are aware. We give examples from the 15th c. to the 21st. In transcription, a\ua0colon marks long vowels, and M, nasalized ones. Retroflexion is shown by capitalization, and\ua0aspiration by h, also a consonant by itself. Glosses are given, some also /morpheme-wise/.Kannada (KAN) and Tamil (TAM) share features with TEL that help make L(R)’s: fairly free word\ua0order, agglutinative particles, and adjectives and relative clauses preceding the noun. We give\ua0only lone KAN and TAM examples, but expect to find more when we search. Hindi (HIN) shares\ua0fewer features with TEL; perhaps therefore, we have so far looked but found few (L)R s in HIN