Growth of high-quality single-crystalline InSb layers remains challenging in material science. Such layered InSb materials are highly desired for searching for and manipulation of Majorana fermions in solid state, a fundamental research task in physics today, and for development of novel high-speed nanoelectronic and infrared optoelectronic devices. Here we report on a new route towards growth of single-crystalline, layered InSb materials. We demonstrate the successful growth of free-standing, two-dimensional InSb nanosheets on one-dimensional InAs nanowires by molecular-beam epitaxy. The grown InSb nanosheets are pure zinc-blende single crystals. The length and width of the InSb nanosheets are up to several micrometers and the thickness is down to ~10 nm. The InSb nanosheets show a clear ambipolar behavior and a high electron mobility. Our work will open up new technology routes towards the development of InSb-based devices for applications in nanoelectronics, optoelectronics and quantum electronics, and for study of fundamental physical phenomena.*To whom correspondence should be addressed. E-mail: jhzhao@red.semi.ac.cn (J.H.Z.); hqxu@pku.edu.cn (H.Q.X.)Over the past several decades, the inherent scaling limitations of Si electron devices have fuelled the exploration of alternative semiconductors, with high carrier mobility, to further enhance device performance [1][2][3] . In particular, high mobility III-V compound semiconductors have been actively studied 4,5 . As a technologically important III-V semiconductor, InSb is the most desired material system for applications in high-speed, low-power electronics and infrared optoelectronics owing to its highest electron mobility and narrowest bandgap among all the III-V semiconductors. Recently, epitaxially grown InSb nanostructures have been widely anticipated to have potential applications in spintronics, topological quantum computing, and detection and manipulation of Majorana fermions, due to small effective mass, strong spin-orbit interaction and giant g factor in InSb [6][7][8][9][10][11][12][13][14][15][16][17][18] . All these applications require a high degree of InSb growth control on its morphology and especially crystal quality 19,20 . Unfortunately, due to the intrinsic largest lattice parameter of InSb among all the III-V semiconductors, epitaxial growth of InSb layers faces an inevitable difficulty in finding a lattice-matched substrate. Conventionally, buffer layers with graded or abrupt composition profile are deposited on lattice mismatched substrates to obtain a layer with a required value of lattice constant 21,22 . Nevertheless, even when the sophisticated buffer-layer engineering is used, the density of dislocations threading to the surface of the buffer from its interface with a lattice mismatched substrate is often too high to grow a high crystal quality InSb layer for fabrication of high-performance nanoelectronics and quantum devices and for study of novel physical phenomena.Here, we report on the successful growth of novel free-standing...

Quantum Griffiths singularity was theoretically proposed to interpret the phenomenon of divergent dynamical exponent in quantum phase transitions. It has been discovered experimentally in three-dimensional (3D) magnetic metal systems and two-dimensional (2D) superconductors. But, whether this state exists in lower dimensional systems remains elusive. Here, we report the signature of quantum Griffiths singularity state in quasi-one-dimensional (1D) Ta2PdS5 nanowires. The superconducting critical field shows a strong anisotropic behavior and a violation of the Pauli limit in a parallel magnetic field configuration. Current-voltage measurements exhibit hysteresis loops and a series of multiple voltage steps in transition to the normal state, indicating a quasi-1D nature of the superconductivity. Surprisingly, the nanowire undergoes a superconductor-metal transition when the magnetic field increases. Upon approaching the zero-temperature quantum critical point, the system uncovers the signature of the quantum Griffiths singularity state arising from enhanced quenched disorders, where the dynamical critical exponent becomes diverging rather than being constant.

Low-dimensional narrow band gap III–V compound semiconductors, such as InAs and InSb, have attracted much attention as one of promising platforms for studying Majorana zero modes and non-Abelian statistics relevant for topological quantum computation. So far, most of experimental studies were performed on hybrid devices based on one-dimensional semiconductor nanowires. In order to build complex topological circuits toward scalable quantum computing, exploring high-mobility two-dimensional (2D) III–V compound electron system with strong spin–orbit coupling is highly desirable. Here, we study quantum transport in high-mobility InSb nanosheet grown by molecular-beam epitaxy. The observations of Shubnikov-de Hass oscillations and quantum Hall states, together with the angular dependence of magnetotransport measurements, provide the evidence for the 2D nature of electronic states in InSb nanosheet. The presence of strong spin–orbit coupling in the InSb nanosheet is verified by the low-field magnetotransport measurements, characterized by weak antilocalization effect. Finally, we demonstrate the realization of high-quality InSb nanosheet–superconductor junctions with transparent interface. Our results not only advance the study of 2D quantum transport but also open up opportunities for developing hybrid topological devices based on 2D semiconducting nanosheets with strong spin–orbit coupling.

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In this study, the realization of mesoscopic Josephson junctions based on free-standing InSb nanosheet grown by molecular-beam epitaxy is reported. Below the critical temperature of superconducting aluminium electrodes (%1.1 K), the high transparency of the contacts gives rise to proximityinduced superconductivity. A dissipationless supercurrent which can be modulated by a gate voltage acting on the electron density in the nanosheet flows through the superconducting weak links. At finite bias voltage, subharmonic energy-gap structures (SGS) originating from multiple Andreev reflections (MARs) are observed, indicating a highly transparent InSb nanosheet-superconductor interface. At last, a superconducting hybrid device with niobium electrodes is shown, suitable for further higher temperature and magnetic field transport measurements.

Paramisgurnus dabryanus (Cypriniformes; Cobitidae), has been an emerging aquaculture species in China since the 1990s. In this study, random amplified polymorphic DNA fingerprinting with 220 primers was used to identify a sex-specific DNA marker in pooled DNA and individual DNA samples from male and female P. dabryanus. One primer, S2115, produced a novel sex-specific DNA fragment found only in tested females. This female-specific fragment was 917 bp with 36% GC content, and was named Pdff1. To further validate the authenticity of this female-specific marker for sexing, two PCR primers (pdff1-F and -R) were designed according to the cloned female-specific sequence. Amplification showed bands specific for females. Dot blot and Southern blot hybridization experiments both displayed female specificity using this marker as the probe. Two other P. dabryanus populations were tested by dot blot hybridization with the Pdff1 probe. The hybridization signals were seen in 33 or 43% of males in addition to all females in the Jinan and Xichuan populations, respectively. We propose to use this sex-specific marker to rapidly and specifically identify the gender of P. dabryanus from the ancient Yellow River Wetland in Yanjin, Henan Province. Our results could assist in cloning sex-specific chromosomal regions.

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