Delocalization of Cooper pairs by doping ?

This is definitely a very wonderful step forward. Have not read it yet, but eager to tomorrow.
http://www.nature.com/nature/journal/v472/n7344/pdf/nature09998.pdf

What is expected of reviewers

I like his viewpoint:

http://www.nature.com/news/2011/110427/full/472391a.html?WT.ec_id=NATURE-20110428

Electron induced rippling in graphene

Physicists are really blessed by nature in the sense that, they have all the time been offered some new objects that admit very rich phenomena to be explored. Latest examples include Graphene and Topological Insulators. Since its discovery, graphene never stops yielding surprising things for physicists. This time comes something that (again, considering Dirac physics) parallels particle physics: the strain field associated with the flexural phonon condenses in the same way as the Higgs field in the Standard Model [1]. Don't miss reading it !

[1]PRL, 106:045502(2011)

Where enter the doped holes in cuprates？

Years have elapsed without a consensus on the full microscopic understanding of the physics involved in cuprate superconductors. One problem central to experimentalists is the residence of doped holes. Although widely held that at low concentrations of dopants, most holes go to Zhang-Rice orbital, whose character is essentially of planar O p orbital, what happens in the overdoped case is still not clear. In this Science report [1], the workers used high resolution Compton scattering to resolve this issue. They claimed that, doped holes are mostly of Cu d character in the OD case. Their results resonate with a two-orbital model [2] that takes into account both dz^2 and dx^2-y^2 orbital. In ref.[2], the energy difference between these orbital, Delta, is the key parameter in determining Tc. Larger Delta gives larger Tc. What is implied in [1], is perhaps that, such Delta should depend on doping x. As x increases, Delta decreases. This might explain the fact that, the SC dome has a small collapse at its up right corner.

Is there a sharp transition ?

[1]Science, 332:698(2011)
[2]PRL, 105:057003(2010)

I would like to mention another paper, which measures orbital current in CuO[Science, 332:696(2011)].

Heat Flow In Small Things

Heat flow is definitely a very interesting problem in physics and also other disciplines. Here is a review on the present status of understanding over this subject concerned with small dimensions.

Advances in the fabrication and characterization of nanoscale systems now allow for a better understanding of one of the most basic issues in science and technology: the flow of heat at the microscopic level. In this Colloquium recent advances are surveyed and an understanding of physical mechanisms of energy transport in nanostructures is presented, focusing mainly on molecular junctions and atomic wires. Basic issues are examined such as thermal conductivity, thermoelectricity, local temperature and heating, and the relation between heat current density
and temperature gradient—known as Fourier’s law. Both theoretical and experimental progress are critically reported in each of these issues and future research opportunities in the field are discussed. [REVIEW OF MODERN PHYSICS, VOLUME 83, JANUARY–MARCH 2011]

Cellular networks

Cellular networks are common in nature, such as seen in the cells, bubbles, and polycrystals. In all these problems, a central question is, how do the cell boundaries distribute in time in their geometric structures and textures ? A key phenomena is that, at large times, the evolution of the distribution ubiquitously leads to a steady state that follows Boltzman's law. Here is an attempt to address this problem. The approach is traditional and phenomenological.

Mesoscale experiment and simulation permit harvesting information about both geometric features and texture in polycrystals. The grain boundary character distribution (GBCD) is an empirical distribution of the relative length [in two dimensions (2D)] or area (in 3D) of an interface with a given lattice misorientation and normal. During the growth process, an initially random distribution of boundary types reaches a steady state that is strongly correlated to the interfacial energy density. In simulation, it is found that if the given energy density depends only
on lattice misorientation, then the steady-state GBCD and the energy are related by a Boltzmann distribution. This is among the simplest nonrandom distributions, corresponding to independent trials with respect to the energy. In this paper, we derive an entropy-based theory that suggests that the evolution of the GBCD satisfies a Fokker-Planck equation, an equation whose stationary state is a Boltzmann distribution. Cellular structures coarsen according to a local evolution law, curvature-driven growth, and are limited by space-filling constraints. The interaction between the evolution law and the constraints is governed primarily by the force balance at triple junctions, the natural boundary condition associated with curvature-driven growth, and determines a dissipation relation. A simplified coarsening model is introduced that is driven by the boundary conditions and reflects the network level dissipation relation of the grain growth system. It resembles an ensemble of inertia-free spring-mass dash pots. Application is made of the recent characterization of Fokker-Planck kinetics as a gradient flow for a free energy in deriving the theory. The theory predicts the results of large-scale two-dimensional simulations and
is consistent with experiment. [PHYSICAL REVIEW B 83, 134117 (2011)]

Giant Electroresistance

There are many devices that are of fundamental interest. The most latest and famous may be the one invented by Fert et al., which displays giant magnetoresistance. In the past few years, there have appeared a flurry of work exploiting ferroelectrics as the barrier layer. I have mentioned quite a number of them in this blog. Here comes a new one. It is made up by sandwiching a BTO layer with two LSMO at different dopings. All these efforts are clearly directed to manipulate the interweaving properties of spin, charge and orbital degrees.

A giant tunneling electroresistance effect may be achieved in a ferroelectric tunnel junction by exploiting the magnetoelectric effect at the interface between the ferroelectric barrier and a magnetic La1 xSrxMnO3 electrode. Using first-principles density-functional theory we demonstrate that a few magnetic monolayers of La1 xSrxMnO3 near the interface act, in response to ferroelectric polarization
reversal, as an atomic-scale spin valve by filtering spin-dependent current. This produces more than an order of magnitude change in conductance, and thus constitutes a giant resistive switching effect. [PRL 106, 157203 (2011)]