JPCM: 2009 highlights, now free for reading until the end of this year

JPCM has produced its 2009 highlights. The good news is that they are available for free till the end of this year. I would like to suggest the following pieces:

[1]The transport properties of graphen,

N M R Peres 2009 J. Phys.: Condens. Matter 21 323201,

We review the transport properties of graphene, considering both the case of bulk graphene and that of nanoribbons of this material at zero magnetic field. We discuss: Klein tunneling, transport by evanescent waves when the chemical potential crosses the Dirac point, the conductance of narrow graphene ribbons, the optical conductivity of pristine graphene, and the effect of disorder on the DC conductivity of graphene.

[2] Magnetic field induced confinement–deconfinement transition in graphene quantum dot,

G Giavaras et al 2009 J. Phys.: Condens. Matter 21 102201

Massless Dirac particles cannot be confined by an electrostatic potential. This is a problem for making graphene quantum dots but confinement can be achieved with a magnetic field and here general conditions for confined and deconfined states are derived. There is a class of potentials for which the character of the state can be controlled at will. Then a confinement–deconfinement transition occurs which allows the Klein paradox to be probed experimentally in graphene dots. A dot design suitable for this experiment is presented.

[3]Exact mapping of the d_x²−y² Cooper-pair wavefunction onto the spin fluctuations in cuprates: the Fermi surface as a driver for 'high T_c' superconductivity

Ross D McDonald et al 2009 J. Phys.: Condens. Matter 21 012201

We propose that the extraordinarily high superconducting transition temperatures in the cuprates are driven by an exact mapping of the d_x²−y² Cooper-pair wavefunction onto the incommensurate spin fluctuations observed in neutron-scattering experiments. This is manifested in the direct correspondence between the inverse of the incommensurability factor δ seen in inelastic neutron-scattering experiments and the measured superconducting coherence length ξ₀. Strikingly, the relationship between ξ₀ and δ is valid for both La_2−xSr_xCuO₄ and YBa₂Cu₃O_7−x, suggesting a common mechanism for superconductivity across the entire hole-doped cuprate family. Using data from recent quantum-oscillation experiments in the cuprates, we propose that the fluctuations responsible for superconductivity are driven by a Fermi-surface instability. On the basis of these findings, one can specify the optimal characteristics of a solid that will exhibit 'high T_c' superconductivity.