Discovery of parity-violating Majorana fermions in a chiral superconductor Sr2RuO4

We found parity-violating Majorana fermions in a chiral superconductor Sr2RuO4. The current-voltage curves show an anomalous behavior: The induced voltage is an even function of the bias current. The magnetic field dependent results suggest the excitation of the Majorana fermions along the closed chiral edge current of the single domain under bias current. We also discuss the relationship between a change of the chirality and spontaneous magnetization of the single domain Sr2RuO4

Ascertaining the Ideality of Photometric Stereo Datasets under Unknown Lighting

The standard photometric stereo model makes several assumptions that are rarely verified in experimental datasets. In particular, the observed object should behave as a Lambertian reflector, and the light sources should be positioned at an infinite distance from it, along a known direction. Even when Lambert’s law is approximately fulfilled, an accurate assessment of the relative position between the light source and the target is often unavailable in real situations. The Hayakawa procedure is a computational method for estimating such information directly from data images. It occasionally breaks down when some of the available images excessively deviate from ideality. This is generally due to observing a non-Lambertian surface, or illuminating it from a close distance, or both. Indeed, in narrow shooting scenarios, typical, e.g., of archaeological excavation sites, it is impossible to position a flashlight at a sufficient distance from the observed surface. It is then necessary to understand if a given dataset is reliable and which images should be selected to better reconstruct the target. In this paper, we propose some algorithms to perform this task and explore their effectiveness

Electronic Properties of Topological Materials: Optical Excitations in Moebius Conjugated Polymers

Electronic structures and optical excitations in Moebius conjugated polymers are studied theoretically. Periodic and Moebius boundary conditions are applied to the tight binding model of poly(para-phenylene), taking exciton effects into account. We discuss that oligomers with a few structural units are more effective than polymers for observations of effects of discrete wave numbers that are shifted by the change in boundary condition. Next, calculations of optical absorption spectra are reported. Certain components of optical absorption for an electric field perpendicular to the polymer axis mix with absorption spectra for an electric field parallel to the polymer axis. Therefore, the polarization dependences of an electric field of light enable us to detect whether conjugated polymers have the Moebius boundary.Comment: 10 pages, 6 figures, to be published in J. Phys. Soc. Jpn., Vol. 74 No. 2 (February, 2005), Letter sectio

Chiral charge-density-waves

We discovered the chirality of charge density waves (CDW) in 1T-TiSe$_2$ by using scanning tunnelling microscopy (STM) and optical ellipsometry. We found that the CDW intensity becomes $I{a_1}:I{a_2}:I{a_3} = 1:0.7 \pm 0.1:0.5 \pm 0.1$, where $Ia_i$ (i =1, 2, 3) is the amplitude of the tunnelling current contributed by the CDWs. There were two states, in which the three intensity peaks of the CDW decrease \textit{clockwise} and \textit{anticlockwise} when we index each nesting vector in order of intensity in the Fourier transformation of the STM images. The chirality in CDW results in the three-fold symmetry breaking. Macroscopically, two-fold symmetry was indeed observed in optical measurement. We propose the new generalized CDW chirality H_{CDW} \equiv {\boldmath q_1} \cdot ({\boldmath q_2}\times {\boldmath q_3}), where {\boldmath q_i} are the nesting vectors, which is independent of the symmetry of components. The nonzero $H_{CDW}$ - the triple-{\boldmath q} vectors do not exist in an identical plane in the reciprocal space - should induce a real-space chirality in CDW system.Comment: 12 pages, 4 figure

Geometrically Frustrated Crystals: Elastic Theory and Dislocations

Elastic theory of ring-(or cylinder-)shaped crystals is constructed and the generation of edge dislocations due to geometrical frustration caused by the bending is studied. The analogy to superconducting (or superfluid) vortex state is pointed out and the phase diagram of the ring-crystal, which depends on radius and thickness, is discussed.Comment: 4 pages, 3 figure

Magnetic Structure of Nano-Graphite Moebius Ribbon

We consider the electronic and magnetic properties of nanographite ribbon with zigzag edges under the periodic or Moebius boundary conditions. The zigzag nano-graphite ribbons possess edge localized states at the Fermi level which cause a ferrimagnetic spin polarization localized at the edge sites even in the very weak Coulomb interaction. The imposition of the Moebius boundary condition makes the system non-AB-bipartite lattice, and depress the spin polarization, resulting in the formation of a magnetic domain wall. The width of the magnetic domain depends on the Coulomb interaction and narrows with increasing U/t.Comment: 4 pages; 6 figures; published at J. Phys. Soc. Jpn. Vol. 72 No. 5 pp. 998-1001 (2003

Cohexisting Medullary and Papillary Thyroid Cancer

Purpose: Papillary thyroid carcinomas (PTCs) and medullary thyroid carcinomas (MTCs) have always been considered different in terms of their incidence rates, cell origins, and histopathological features. Simultaneous occurrence of both disease entities is very rare. Methods: We describe a series of cases with simultaneous MTC and PTC occurrences in the thyroid gland. Results: From 2,897 patients (mean age, 49.2±12.5; 81% women) who underwent thyroidectomy for cancer between 2000 and 2015, we reviewed 11 cases of simultaneous occurrence of MTCs and PTCs. Multifocal PTC with simultaneous MTC was detected in 5 of the 11 cases (45%). Of these PTC patients, 2 had 2 foci, 2 had 3 foci, and 1 had 4 foci. There was 1 case of multifocal MTC with solitary PTC. One patient presented with “composite thyroid carcinoma” with mixed features of MTCs and PTCs. Eight patients (72%) presented an association with diffuse lymphocytic thyroiditis. The sizes of the tumors were 1.95±0.23 cm vs. 1.20±0.20 cm for PTCs and MTCs, respectively (P=0.531). The prevalence of extrathyroidal extension was 33.1% vs. 30.2% for PTCs and MTCs, respectively (P=0.282). All patients underwent total thyroidectomy and central neck node dissection. Radio iodine was delivered to 44% of patients. Follow-up review revealed 9 disease-free patients and 1 with local neck recurrence, while 1 patient died due to non-thyroid reasons. Conclusion: There are only 30 reports describing a total of 50 cases in the English literature regarding concurrent PTC and MTC in the same gland. This study represents one of the largest case series. Whether the incidence of another cancer in these patients is coincidental, or due to the possible activation of a common tumorigenic pathway for both follicular and parafollicular thyroid cells, remains to be elucidated

PENGABDIAN KKN-MANDIRI TEMATIK KELURAHAN ONEKORE KABUPATEN ENDE

The general theme of the 2020 Community Service Program is “Community Empowerment”. Meanwhile, the special theme is "Entrepreneurship". The implementation time starts from August 3 to September 3, 2020, in Onekore Village, Ende Tengah District, Ende Regency. On the program. With this special theme, the main activity carried out is supporting entrepreneurship in Onekore Village. The purpose of implementing this activity is that students are expected to gain learning experience through direct involvement in the community in finding, formulating, solving, and overcoming problems in the field. In this KKN activity, the problems found were the lack of utilization of existing garden products, namely bananas. So far, it is consumed by boiling or eating it without further processing. Olso besides, we also found woven products from weaving that were difficult to market. Students socialize and practice entrepreneurship as an effort to solve problems faced by weaving craftsmen. Efforts made to help the household economy include making flower pots and making wallets made from woven fabrics. Supporting activities during the Community Service Program are assisting with the administration of the Village, community service, building a gate for the Indonesian Independence Day, making sample gardens, socializing COVID-19 and, health service for the elderly

Suppression of 2D superconductivity by the magnetic field: quantum corrections vs superconductor-insulator transition

Magnetotransport of superconducting Nd_{2-x}Ce_xCuO_{4+y} (NdCeCuO) films is studied in the temperature interval 0.3-30 K. The microscopic theory of the quantum corrections to conductivity, both in the Cooper and in the diffusion channels, qualitatively describes the main features of the experiment including the negative magnetoresistance in the high field limit. Comparison with the model of the field-induced superconductor-insulator transition (SIT) is included and a crossover between these two theoretical approaches is discussed.Comment: 5 pages, 4 figures. Submitted to JETP Letter