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We have observed spin splitting and band gap structure in the Si[110] direction by doping with impurities, which is manifested by a significant opening of the spin-splitting energy level in the localized states. Interestingly, the opening effect occurs such that the electronic spin states are embedded in the localized states on the surface. Here, the broken symmetry obviously appears in the system. In the simulation calculation, it is observed that the spin-splitting gap of the electronic spin levels can be opened over 500 meV in the localized states for the Si=O double bond for doped Si[110] nanowires with a diameter of 0.4 nm. Si[110] nanowire structures doped with oxygen were prepared on silicon wafers using a combination of nanosecond pulsed laser deposition (PLD) and coherent electron beam irradiation studied comparatively in experiments. By combining the experimental and computational results, the physical model on the coupling between the electronic spin states and the localized states was constructed, which will have good application potential in the fields of the electronic spin qubit, quantum information storage, and quantum information processing. [ABSTRACT FROM AUTHOR]

A new birefringent crystal, C10H6NO2Cd(NO3)·2H2O, was designed by combining a π-conjugated [C10H6NO2]− group with a CdO7N polyhedron. Notably, the experimental energy gap is 0.02 eV higher than that of the organic raw material, which resulted from a covalent edge-sharing connection, implying a new strategy to improve the band-gap of birefringent materials. [ABSTRACT FROM AUTHOR]

Common nonlinear optical (NLO) crystals consist of traditional functional building blocks with inherent optical limitation. Herein, inspired by traditional (B3O6)3− inorganic building block, we theoretically identified a new type of organic functional building blocks and then successfully synthesized the first cyamelurate NLO crystal, Ba(H2C6N7O3)2 ⋅ 8 H2O. To our surprise, the constituent (H2C6N7O3)− building block is not in structurally optimal arrangement, but Ba(H2C6N7O3)2 ⋅ 8 H2O exhibits excellent optical properties including wide band gap of 4.10 eV, very large birefringence of 0.24@550 nm, and exceptionally strong second‐harmonic generation (SHG) response of about 12×KH2PO4. Both the SHG response and birefringence are much larger than those of commercial NLO crystal β‐BaB2O4 with optimally aligned (B3O6)3− building block. Theoretical calculations suggest that the expanded π‐conjugation delocalization within (H2C6N7O3)−vs (B3O6)3− should be responsible to the enhanced performance. This work implies that there is still much room to develop new NLO crystals with excellent functional building blocks that may be longly neglected. [ABSTRACT FROM AUTHOR]