Viewpoints

Shuang Zhang, Xiang Zhang, Physics 2, 91 (2009) – Published November 2, 2009

Optics Particles & Fields Metamaterials

Čerenkov radiation with the emission cone reversed has been observed in a metamaterial with negative refractive index.

John R. Kirtley, Francesco Tafuri, Physics 2, 92 (2009) – Published November 2, 2009

Mesoscopics Cosmology

Defects—in the form of vortices in superconductors or “strings” in the fabric of the universe—can reveal the state of a system at the time it was cooled.

Howard A. Stone, Alison M. Forsyth, Jiandi Wan, Physics 2, 89 (2009) – Published October 26, 2009

Fluid Dynamics Biological Physics

Simulations provide insight into how viscous flow transforms the shapes of red blood cells, which may influence their physiological properties.

Subir Sachdev, Physics 2, 90 (2009) – Published October 26, 2009

Statistical Mechanics Strongly Correlated Materials

A new renormalization group approach that maps lattice problems to tensor networks may hold the key to solving seemingly intractable models of strongly correlated systems in any dimension.

Mattias Marklund, Lennart Stenflo, Physics 2, 86 (2009) – Published October 19, 2009

Optics Fluid Dynamics

How freak or rogue waves form in the ocean is not well understood, but new investigations suggest a mechanism for these waves that may also allow formation of high-intensity pulses in optical fibers.

Marco Polini, Giovanni Vignale, Physics 2, 87 (2009) – Published October 19, 2009

Atomic & Molecular Physics

Interactions among noncondensed bosonic atoms in a trap can cause one species of atoms accelerated by a magnetic field to drag along another species of atoms that would normally not interact with the field.

J. O. Sofo, R. D. Diehl, Physics 2, 84 (2009) – Published October 12, 2009

Mesoscopics Graphene

Photoelectron spectroscopy reveals how carbon atoms aggregate to form domelike graphene structures on iridium surfaces.

Robert F. Klie, Physics 2, 85 (2009) – Published October 12, 2009

Optics Nanophysics

A new approach to reduce spherical and chromatic aberration in electron microscopy allows for low-energy imaging of single-layer boron nitride, a novel 2D nanostructure that is analogous to graphene.

Joel E. Moore, Physics 2, 82 (2009) – Published October 5, 2009

Quantum Information Semiconductor Physics Mesoscopics Nanophysics

A theoretical analysis of recent experiments suggests that a key feature of a topological quantum computer—the unusual statistics of quasiparticles in the quantum Hall effect—may finally have been observed.

Alexander Lvovsky, Physics 2, 83 (2009) – Published October 5, 2009

Quantum Information Optics

An entangled state of six photons could potentially carry quantum information over large distances and between different reference frames.

Dan M. Stamper-Kurn, Physics 2, 80 (2009) – Published September 28, 2009

Atomic & Molecular Physics

New methods for lowering the entropy of ultracold gases may allow observation of more subtle quantum materials.

Peter B. Weichman, Physics 2, 81 (2009) – Published September 28, 2009

Superfluidity

The existence, through statistical fluctuation, of arbitrarily large regions with a certain order in an otherwise disordered system, allow one to set bounds on various important thermodynamic properties.

Thierry Giamarchi, Physics 2, 78 (2009) – Published September 21, 2009

Strongly Correlated Materials

An angle-resolved photoemission spectroscopy study of electron transport along quasi-one-dimensional Mo-O chains of Li_0.9Mo₆O₁₇ reveals puzzling behavior that does not fit within the available one-dimensional theory frameworks and likely points to undiscovered physics.

Joseph Minahan, Physics 2, 79 (2009) – Published September 21, 2009

Particles & Fields Gravitation

A mathematical formulism makes a step forward in proving the AdS/CFT correspondence that connects quantum mechanics with gravity.

Fernando Luis, Physics 2, 75 (2009) – Published September 14, 2009

Magnetism Nanophysics Spintronics

A microscopic study of magnetic nanoislands on a surface challenges the widely held view that all atoms in a relaxing nanoparticle flip their spins in unison.

Adela Marian , Bretislav Friedrich, Physics 2, 76 (2009) – Published September 14, 2009

Atomic & Molecular Physics

An electric field can be used to pull on molecular hydrogen’s highly excited outer electron to slow down and trap the molecule.

Riccardo Hertel, Physics 2, 73 (2009) – Published September 8, 2009

Optics Magnetism

Magnetic switching is typically a continuous process, where a field pulse rotates a magnet from up to down, but it is now possible to do this faster — and with all-optical methods — by first quenching the magnetization to zero and then repolarizing it in the opposite direction.

Marc J. J. Vrakking, Physics 2, 72 (2009) – Published August 31, 2009

Atomic & Molecular Physics Optics

Calculations show that with new short pulse x-ray light sources, it should be possible to use photoelectron emission to make movies of changes in molecular structure.

Horatiu Nastase, Physics 2, 71 (2009) – Published August 24, 2009

Particles & Fields

A recent theory of gravity has stimulated intense debate and many explorations of its implications.

Hermann Nicolai, Physics 2, 70 (2009) – Published August 17, 2009

Particles & Fields

Quantum field theoretic extensions of Einstein’s theory of gravity tend to suffer from incurable infinities, but a theory called N=8 supergravity may actually avoid them—against expectations held for almost 30 years.

Marivi Fernández-Serra, Physics 2, 67 (2009) – Published August 10, 2009

Atomic & Molecular Physics Statistical Mechanics Soft Matter

Experiments on melting of small water clusters open the door to the study of the size-dependent phase diagram of water.

Klaus Jungmann, Physics 2, 68 (2009) – Published August 10, 2009

Atomic & Molecular Physics Particles & Fields Nuclear Physics

A huge, predicted atomic parity violation has now been observed in ytterbium, further aiding tabletop experimental searches for physics beyond the standard model that complement ongoing efforts at high-energy colliders.

N. W. Ashcroft, Physics 2, 65 (2009) – Published August 3, 2009

Chemical Physics

We can generally understand the way simple chemical combinations arise by assuming a standard valence structure for the elements, but a high-pressure study suggests that the rules for hydrogen may not be so easily pinned down.

Thomas Vojta, Physics 2, 66 (2009) – Published August 3, 2009

Mesoscopics Nanophysics Statistical Mechanics

Quantum states in disordered solids are characterized by wild spatial fluctuations. As a result, the behavior of a single typical wave function differs markedly from the ensemble average.

Karen L. Kavanagh, Physics 2, 63 (2009) – Published July 27, 2009

Semiconductor Physics

A new generation of electron microscopes that correct for spherical aberration may be able to chart the positions of individual atoms as they diffuse through a crystal.