Graphene, a single layer of graphite, has recently attracted considerable attention owing to its remarkable electronic and structural properties and its possible applications in many emerging areas such as graphene-based electronic devices. The charge carriers in graphene behave like massless Dirac fermions, and graphene shows ballistic charge transport, turning it into an ideal material for circuit fabrication. However, graphene lacks a bandgap around the Fermi level, which is the defining concept for semiconductor materials and essential for controlling the conductivity by electronic means. Theory predicts that a tunable bandgap may be engineered by periodic modulations of the graphene lattice, but experimental evidence for this is so far lacking. Here, we demonstrate the existence of a bandgap opening in graphene, induced by the patterned adsorption of atomic hydrogen onto the Moiré superlattice positions of graphene grown on an Ir(111) substrate.

The adsorbate structures of atomic hydrogen on the basal plane of graphene on a SiC substrate is revealed by Scanning Tunneling Microscopy (STM). At low hydrogen coverage the formation of hydrogen dimer structures is observed, while at higher coverage larger disordered clusters are seen. We find that hydrogenation preferentially occurs on the protruding/high tunneling probability areas of the graphene layer modulated by the underlying 6 x 6 reconstruction of SiC. Hydrogenation offers the interesting possibility to manipulate both the electronic and chemical properties of graphene.

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Several studies in management control have drawn upon the concepts of coercive and enabling forms of bureaucracy (Adler and Borys 1996) to discuss how the features of a control system may affect employees' attitudes toward control. This question is relevant because enabling forms of control allow organizations to better manage tensions between efficiency and flexibility, which is arguably a key issue in many organizations today. Our paper contributes to this stream of research by detailing how enabling control functions in the particular setting of new product development. To this end, we draw upon empirical material collected through an in-depth field study carried out in a manufacturing organization. We use data from interviews, participant observation, and internal documentation in this firm to demonstrate how the combination of different control mechanisms helps the organization balance efficiency and flexibility. In addition, our paper sets out to explore how strategic change can influence the operation of enabling control. Focusing on the introduction of a new product strategy in our case organization, we describe employees' repair efforts in adapting the control system to their own needs. We find that these repair efforts are perceived as not wholly satisfactory, which suggests that, in the case of important strategic changes, repair may require more top-down management intervention.