T graphene, a two-dimensional carbon allotrope with tetrarings, is investigated by first-principles calculations. We demonstrate that buckled T graphene has Dirac-like fermions and a high Fermi velocity similar to graphene even though it has nonequivalent bonds and possesses no hexagonal honeycomb structure. New features of the linear dispersions that are different from graphene are revealed. π and π* bands and the two comprising sublattices are the key factors for the emergence of Dirac-like fermions. T graphene and its two types of nanoribbon are expected to possess additional properties over graphene due to its different band structure.

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Although a number of petrographic observations and isotopic data suggest that magma mixing is common in genesis of many granite plutons, it is still controversial whether the mantle-derived magmas were involved in granites. We carried out in this study a systematic analysis of in situ zircon Hf-O isotopes for three early Yanshanian intrusions dated at ca. 160 Ma from the Nanling Range of Southeast China. The Qinghu monzonite has very homogeneous zircon Hf-O isotopic compositions, ε Hf (t) =11.6±0.3 and δ 18 O=5.4‰±0.3‰. In combination with whole-rock geochemical and Sr-Nd isotopic data, the parental magma of the Qinghu monzonite were likely derived from the partial melting of recently-metasomatized, phlogopite-bearing lithospheric mantle without appreciable crustal contamination. The Lisong and Fogang granites and the mafic microgranular enclaves (MME) within the Lisong granites have a wide range of zircon Hf-O isotopic compositions, with Hf and O isotopes being negatively correlated within each pluton. The Lisong MMEs were crystallized from a mantle-derived magma, similar to the parental magma of the Qinghu monzonite, with small amount of crustal assimilation. The Lisong and Fogang granites were formed by reworking of meta-sedimentary materials by mantle-derived magmas and mixing of the mantle-and sediment-derived melts to varying degrees. It is thus concluded that these two Yanshanian granites in the Nanling Range were formed associated with growth and differentiation of continental crust. granites, SIMS, zircon, Hf-O isotopes, mantle Granites are among the most common rocks in the continental crust. Despite relatively simple in rock-forming mineral compositions (including quartz, feldspars and minor amount of mafic minerals), the granite petrogenesis, particularly the role of mantle-derived magma in genesis of the granites, has been long debated [1] .In general, the mantle-derived magma can play roles as heat sources and materials in the genesis of granites. It is widely considered that the mantle magmatism including magmatic underplating and intrusion provides the most important heat sources that result in melting of continental materials to form granites. However, it is controversial whether the mantle magmas were involved in the genesis of granites [2] . The majority of I-and S-type granites in the continental crust were thought to be derived from preexisting infracrustal igneous rocks and supracrustal sedimentary rocks, respectively in terms of the granite classification scheme, precluding a

Defect-induced magnetism is firstly observed in neutron irradiated SiC single crystals. We demonstrated that the intentionally created defects dominated by divacancies (V(Si)V(C)) are responsible for the observed magnetism. First-principles calculations revealed that defect states favor the formation of local moments and the extended tails of defect wave functions make long-range spin couplings possible. Our results confirm the existence of defect-induced magnetism, implying the possibility of tuning the magnetism of wide band-gap semiconductors by defect engineering.

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Gate-tunable junctions are key elements in quantum devices based on hybrid semiconductor–superconductor materials. They serve multiple purposes ranging from tunnel spectroscopy probes to voltage-controlled qubit operations in gatemon and topological qubits. Common to all is that junction transparency plays a critical role. In this study, we grow single-crystalline InAs, InSb, and InAs1–x Sb x semiconductor nanowires with epitaxial Al, Sn, and Pb superconductors and in situ shadowed junctions in a single-step molecular beam epitaxy process. We investigate correlations between fabrication parameters, junction morphologies, and electronic transport properties of the junctions and show that the examined in situ shadowed junctions are of significantly higher quality than the etched junctions. By varying the edge sharpness of the shadow junctions, we show that the sharpest edges yield the highest junction transparency for all three examined semiconductors. Further, critical supercurrent measurements reveal an extraordinarily high I C R N, close to the KO-2 limit. This study demonstrates a promising engineering path toward reliable gate-tunable superconducting qubits.

Nanowires can serve as flexible substrates for hybrid epitaxial growth on selected facets, allowing for design of heterostructures with complex material combinations and geometries. In this work we report on hybrid epitaxy of semiconductor -ferromagnetic insulator -superconductor (InAs/EuS/Al) nanowire heterostructures. We study the crystal growth and complex epitaxial matching of wurtzite InAs / rock-salt EuS interfaces as well as rock-salt EuS / face-centered cubic Al interfaces. Because of the magnetic anisotropy originating from the nanowire shape, the magnetic structure of the EuS phase are easily tuned into single magnetic domains. This effect efficiently ejects the stray field lines along the nanowires. With tunnel spectroscopy measurements of the density of states, we show the material has a hard induced superconducting gap, and magnetic hysteretic evolution which indicates that the magnetic exchange fields are not negligible. These hybrid nanowires fulfil key material requirements for serving as a platform for spin-based quantum applications, such as scalable topological quantum computing.

Intrinsic diamagnetism of graphene is studied both theoretically and experimentally, to unravel the magnetic response of chiral massless fermions. Comprehensive formulas predicting the variation of graphene magnetization with magnetic field and temperature are developed. Graphene magnetization M at low temperatures is particularly large and M ∝ − √ B, intrinsically different from normal materials. The quantum Berry phase of π and linear energy dispersion are responsible for this intriguing macroscopic behavior. The temperature dependence of magnetization is successfully formulated by a Langevin-like function. The de Haas-van Alphen oscillations are predicted in the case of doping. Correspondingly, experiments at different temperatures are conducted on highly pure, mass-produced graphene flakes derived from SiC single crystals, which exhibit very strong diamagnetism. The measured results agree well with the theoretical ones in both magnitude and trend.