Properties of Graphene: A Theoretical Perspective

In this review, we provide an in-depth description of the physics of monolayer and bilayer graphene from a theorist's perspective. We discuss the physical properties of graphene in an external magnetic field, reflecting the chiral nature of the quasiparticles near the Dirac point with a Landau level at zero energy. We address the unique integer quantum Hall effects, the role of electron correlations, and the recent observation of the fractional quantum Hall effect in the monolayer graphene. The quantum Hall effect in bilayer graphene is fundamentally different from that of a monolayer, reflecting the unique band structure of this system. The theory of transport in the absence of an external magnetic field is discussed in detail, along with the role of disorder studied in various theoretical models. We highlight the differences and similarities between monolayer and bilayer graphene, and focus on thermodynamic properties such as the compressibility, the plasmon spectra, the weak localization correction, quantum Hall effect, and optical properties. Confinement of electrons in graphene is nontrivial due to Klein tunneling. We review various theoretical and experimental studies of quantum confined structures made from graphene. The band structure of graphene nanoribbons and the role of the sublattice symmetry, edge geometry and the size of the nanoribbon on the electronic and magnetic properties are very active areas of research, and a detailed review of these topics is presented. Also, the effects of substrate interactions, adsorbed atoms, lattice defects and doping on the band structure of finite-sized graphene systems are discussed. We also include a brief description of graphane -- gapped material obtained from graphene by attaching hydrogen atoms to each carbon atom in the lattice.Comment: 189 pages. submitted in Advances in Physic

A phenomenological approach to the ethics of transplantation medicine : sociality and sharing when living-with and dying-with others

Recent years have seen a rise in the number of sociological, anthropological, and ethnological works on the gift metaphor in organ donation contexts, as well as in the number of philosophical and theological analyses of giving and generosity, which has been mirrored in the ethical debate on organ donation. In order to capture the breadth of this field, four frameworks for thinking about bodily exchanges in medicine have been distinguished: property rights, heroic gift-giving, sacrifice, and gift-giving as aporia. Unfortunately, they all run into difficulties in terms of both making sense of the relational dimensions of postmortem and live organ donations and being normatively adequate in the sense of shedding light and providing guidance on ethical concerns when body parts are donated. For this reason, this article presents a phenomenological framework of giving-through-sharing, based on Maurice Merleau-Pontys philosophy. This framework makes sense of relational dimensions of postmortem and live organ donation. It also sheds light on three highly debated concerns in organ donation ethics: indebtedness on the part of recipients, the fact that some live donors do not experience donation as a matter of choice, and the potentially painful experience of donors relatives, who need to make decisions about postmortem organ donation at a time of bereavement. It can indirectly support what may be called a normalization of bodily exchanges in medicine

Single-crystal diamond nanomechanical resonators with quality factors exceeding one million

ISSN:2041-172