Random phase-free kinoform for large objects

We propose a random phase-free kinoform for large objects. When not using the random phase in kinoform calculation, the reconstructed images from the kinoform are heavy degraded, like edge-only preserved images. In addition, the kinoform cannot record an entire object that exceeds the kinoform size because the object light does not widely spread. In order to avoid this degradation and to widely spread the object light, the random phase is applied to the kinoform calculation; however, the reconstructed image is contaminated by speckle noise. In this paper, we overcome this problem by using our random phase-free method and error diffusion method

Molecular beam epitaxy of superconducting FeSex_{x}Te1−x_{1-x} thin films interfaced with magnetic topological insulators

Engineering heterostructures with various types of quantum materials can provide an intriguing playground for studying exotic physics induced by proximity effect. Here, we report the successful synthesis of iron-based superconductor FeSe$_{x}$Te$_{1-x}$ (FST) thin films in the entire composition of $0 \leq x \leq 1$ and its heterostructure with a magnetic topological insulator by using molecular beam epitaxy. Superconductivity is observed in the FST films with an optimal superconducting transition temperature $T_c$ $\sim$ 12 K at around x = 0.1. We found that superconductivity survives in the very Te-rich films ($x \leq 0.05$), showing stark contrast to bulk crystals with suppression of superconductivity due to an appearance of bicollinear antiferromagnetism accompanied by monoclinic structural transition. By examining thickness t dependence on electrical transport properties, we observed strong suppression of the structural transition in films below t $\sim$ 100 nm, suggesting that substrate effects may stabilize superconducting phase near the interface. Furthermore, we fabricated all chalcogenide-based heterointerface between FST and magnetic topological insulator (Cr,Bi,Sb)$_{2}$Te$_{3}$ for the first time, observing both superconductivity and large anomalous Hall conductivity. The anomalous Hall conductivity increases with decreasing temperature, approaching to the quantized value of $e^2/h$ down to the measurable minimum temperature at $T_c$. The result suggests coexistence of magnetic and superconducting gaps at low temperatures opening at the top and bottom surfaces, respectively. Our novel magnetic topological insulator/superconductor heterostructure could be an ideal platform to explore chiral Majorana edge mode

Possible monitoring of mesophotic scleractinian corals using an underwater mini-ROV to sample coral eDNA

Mesophotic coral ecosystems (MCEs) are light-dependent tropical or subtropical communities occurring at depths of 30–150 m. Broader surveys of MCEs are needed to better understand stony corals, the keystone species of coral-reef ecosystems. While MCEs have been studied by professional SCUBA divers and with deep-sea robots, comprehensive surveys of MCEs are required. An eDNA metabarcoding method has recently been used to survey scleractinian corals in shallow reefs. We tested whether MCEs might be more comprehensively surveyed by collecting seawater samples using an underwater mini-remote operated vehicle (mini-ROV). Seawater was collected 1–2 m above reef tops at depths of 20–80 m at 24 sites in six locations around the Zamami Islands (Okinawa, Japan). Water samples were then subjected to coral-specific eDNA amplification. Metabarcoding analyses of amplicons showed that except for one site, coral-specific eDNA from approximately 0.5 l seawater samples was sufficient to identify genera. The proportion of Acropora eDNA was higher at shallow reefs and upper ridges of slopes, while the proportion of Porites increased at mesophotic sites. Although further technical improvements are required, this study suggests that it may be possible to monitor mesophotic corals to the generic level using eDNA collected using mini-ROVs

Monitoring mesophotic scleractinian corals using an underwater mini-ROV to sample eDNA

Mesophotic coral ecosystems (MCEs) are light-dependent tropical or subtropical communities occurring at depths of 30 to 150 m. We recently devised a coral-specific environmental DNA (eDNA) barcoding method that can identify 36 scleractinian genera in shallow reefs by sampling ~1L of surface seawater. If eDNA barcoding is combined with sampling using underwater mini-Remote Operated Vehicles (mini-ROVs), it may be possible to survey mesophotic corals more easily and broadly. Around the Zamami Islands, in Okinawa, Japan, seawater was collected 1–2 m above the bottom at six locations 20–80 m below the surface and subjected to coral-specific eDNA amplification. Metabarcoding analyses showed that (a) eDNA from ~0.5 L seawater was sufficient to identify genera and to yield comparative ratios of genera at these sites; (b) Acropora dominates shallow reefs and upper ridges of slopes, while other genera including Porites, Pocillopora and Polyphyllia are more abundant at mesophotic sites; (c) one site showed a gradient in which Acropora was replaced by Plesiastrea at increasing depths. Although further technical improvements are required, the use of eDNA and underwater mini-ROVs may permit monitoring of mesophotic corals more broadly and easily.Funding provided by: JST COI-NEXT project*Crossref Funder Registry ID: Award Number: Funding provided by: Okinawa Institute of Science and Technology Graduate UniversityCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100004199Award Number:Seawater samples were collected at reefs around the Zamami Islands on 9-10 March and 23-25 May 2022. Mini-ROV used in this study was FIFISH V6Plus. On the boat, seawater collected by the sampler was moved to 1L bottle and filtered promptly through 0.45-μm Sterivex filters (Merck) using peristaltic pomp. 1 mL of RNAlater (Qiagen) was added to the filtrate to prevent DNA degradation and was maintained at 4℃ before transfer to a -20℃ freezer in the laboratory. eDNA in Sterivex filters was extracted following the Environmental DNA Sampling and Experiment Manual v. 2.1. Extracted eDNA samples were PCR-amplified using primers, Scle_12S_Fw (5'-CCAGCMGACGCGGTRANACTTA-3') and Scle_12S_Rv (5'-AAWTTGACGACGGCCATGC-3'), for mitochondrial 12S rRNA genes of scleractinian corals. PCR amplification was carried out Tks Gflex DNA Polymerase (Takara) under cycling conditions of 1 min at 94°C, followed by 35 cycles of 10 s at 98°C, 15 s at 60°C and 30 s at 68°C, with an extension of 5 min at 68°C in the final cycle. PCR products were extracted and cleaned with a FastGene Gel/PCR Extraction Kit (NIPPON Genetics Co., Ltd.). Amplicon sequencing libraries of cleaned PCR products were prepared using a KAPA Hyper Prep Kit (NIPPON Genetics) without fragmentation. Libraries were multiplexed and 300-bp paired-end reads were sequenced on a MiSeq platform (Illumina) using a MiSeq Reagent kit v3 (600 cycles)