No abstract

The χ(b)(nP) quarkonium states are produced in proton-proton collisions at the Large Hadron Collider at sqrt[s] = 7  TeV and recorded by the ATLAS detector. Using a data sample corresponding to an integrated luminosity of 4.4  fb(-1), these states are reconstructed through their radiative decays to Υ(1S,2S) with Υ → μ+ μ-. In addition to the mass peaks corresponding to the decay modes χ(b)(1P,2P) → Υ(1S)γ, a new structure centered at a mass of 10.530 ± 0.005(stat) ± 0.009(syst)  GeV is also observed, in both the Υ(1S)γ and Υ(2S)γ decay modes. This structure is interpreted as the χ(b)(3P) system.

Broadband photodetection is central to various technological applications including imaging, sensing and optical communications. On account of their Dirac-like surface state, Topological insulators (TIs) are theoretically predicted to be promising candidate materials for broadband photodetection from the infrared to the terahertz. Here, we report a vertically-constructed ultra-broadband photodetector based on a TI Bi2Te3-Si heterostructure. The device demonstrated room-temperature photodetection from the ultraviolet (370.6 nm) to terahertz (118 μm) with good reproducibility. Under bias conditions, the visible responsivity reaches ca. 1 A W(-1) and the response time is better than 100 ms. As a self-powered photodetector, it exhibits extremely high photosensitivity approaching 7.5 × 10(5) cm(2) W(-1), and decent detectivity as high as 2.5 × 10(11) cm Hz(1/2) W(-1). In addition, such a prototype device without any encapsulation suffers no obvious degradation after long-time exposure to air, high-energy UV illumination and acidic treatment. In summary, we demonstrate that TI-based heterostructures hold great promise for addressing the long lasting predicament of stable room-temperature high-performance broadband photodetectors.

High-performance broadband photodetectors have recently attracted signifi cant interest [1][2][3][4][5] because of their importance to a variety of applications, including imaging, remote sensing, environmental monitoring, astronomical detection, photometers and analytical applications. Graphene is a promising material for broadband photodetection applications because of its ability to absorb incident light over a wide wavelength range, from at least the visible (VIS) spectrum to the infrared. [ 6 ] Recent works have demonstrated that zerobandgap single-or few-layer graphene-based photodetectors based on a fi eld-effect transistor (FET) structure could operate in the near-infrared (NIR) and VIS parts of the electromagnetic spectrum. [ 7,8 ] However, no working spectra have been demonstrated for these zero-bandgap graphene photodetectors in longer wavelength ranges. Theoretical calculations indicated that opening and varying the bandgap of

We demonstrate that a square lattice of artificial pinning centers in a superconducting Nb film induces the formation of highly ordered interstitial vortex phases with different symmetries for external magnetic fields as high as the eighth matching field. These ''supermatching'' phases are identified by distinct differences in the behavior of their critical currents, magnetoresistivity, and magnetization. Our results are consistent with predictions of supermatching lattice symmetries by recent numerical simulations. ͓S0163-1829͑99͒51142-9͔ RAPID COMMUNICATIONS R12 586 PRB 60 V. METLUSHKO et al. RAPID COMMUNICATIONS PRB 60 R12 587 INTERSTITIAL FLUX PHASES IN A . . . RAPID COMMUNICATIONS R12 588 PRB 60 V. METLUSHKO et al.