Browse Physics

Ulrich Schollwöck, Physics 2, 39 (2009) – Published May 11, 2009

Quantum Information Quantum Mechanics

A new algorithm allows for the extremely efficient calculation of thermally averaged quantities in one dimension, in conjunction with the density matrix renormalization group method. The key is the judicious selection of a few representative states.

Carsten Timm, Physics 2, 35 (2009) – Published May 4, 2009

Magnetism

Transport measurements show evidence of a topologically nontrivial structure—a lattice of skyrmions—in intermetallic MnSi.

Ralf Metzler, Physics 2, 36 (2009) – Published May 4, 2009

Statistical Mechanics Biological Physics

Faster does not mean more precise—a new view of how proteins diffuse and bind to a specific site on the DNA reassesses the role noise plays in the biochemical production line that creates biomolecules from genes.

Bruce Winstein, Kathryn M. Zurek, Physics 2, 37 (2009) – Published May 4, 2009

Particles & Fields Astrophysics Cosmology

New results from the Fermi Gamma-Ray Space Telescope, the most precise to date in the energy range 20 GeV to 1 TeV, should help resolve whether cosmic rays composed of the lightest charged particles, i.e., electrons and positrons, come from dark matter or some other astrophysical source.

Sandu Popescu, Physics 2, 32 (2009) – Published April 27, 2009

Optics Quantum Mechanics

In the weird world of quantum mechanics, looking at time flowing backwards allows us to look forward to precision measurements.

David A. Reis, Physics 2, 33 (2009) – Published April 27, 2009

Optics

The observation of squeezed phonons by x-ray diffraction allows researchers to study the interactions between ultrafast lasers and matter in a whole new light.

Antonio H. Castro Neto, Physics 2, 30 (2009) – Published April 20, 2009

Mesoscopics Graphene

Graphene, believed to be a semimetal so far, might actually be an insulator when suspended freely.

Henning Moritz, Tilman Esslinger, Physics 2, 31 (2009) – Published April 20, 2009

Atomic & Molecular Physics

In a cooled and trapped cloud of ytterbium atoms, the transition from a superfluid to an insulating state has been observed, opening up new possibilities for precision measurements, optical clocks, and quantum computing.

Göran Grimvall, Physics 2, 28 (2009) – Published April 13, 2009

Materials Science

An old problem in solid-state physics is the difficulty of theory to account accurately for the heat capacity of solids close to their melting points.

Dieter Jaksch, Physics 2, 29 (2009) – Published April 13, 2009

Atomic & Molecular Physics

Inelastic light scattering is used to study correlated phases of one-dimensional Bose gases. This spectroscopic technique can distinguish superfluid and insulating phases and allow identification of the transition from one to the other.

B. D. Esry, Physics 2, 26 (2009) – Published April 6, 2009

Atomic & Molecular Physics

An ultracold atomic physics experiment reveals universal physics in a four-body system.

Jason R. Petta, Physics 2, 27 (2009) – Published April 6, 2009

Magnetism Semiconductor Physics

A quantum dot refrigerator that cools an electron gas close to 100 mK may allow experimentalists to better probe electron-electron interactions in quantum confined systems.

Yoseph Imry, Physics 2, 24 (2009) – Published March 30, 2009

Mesoscopics

The surprising prediction that currents can flow forever in small normal metal rings was confirmed almost twenty years ago. Highly precise new experiments find good agreement with theory that was not seen till now.

Gediminas Juzeliūnas, Physics 2, 25 (2009) – Published March 30, 2009

Atomic & Molecular Physics

Trapped cold atom gases mimic much of the behavior of electrons in a solid, but because the atoms are neutral, it is difficult to imitate the physics of electrons moving in a magnetic field. Now, experiments show that a suitable combination of lasers can create an artificial magnetic field for cold atoms.

Fabio Marchesoni, Physics 2, 23 (2009) – Published March 23, 2009

Atomic & Molecular Physics Interdisciplinary Physics

Stochastic resonance, in which a periodic signal applied to a nonlinear system can be amplified by adding noise, has been observed in a mechanical system and predicted to occur in a Bose-Einstein condensate.

Gilad Perez, Physics 2, 21 (2009) – Published March 16, 2009

Particles & Fields

Study of variations in the mass and interactions of quarks may reveal whether fundamental constants are governed by “environmental selection rules” that lead to complex universes capable of having observers.

Ernst Helmut Brandt, Shi-Ping Zhou, Physics 2, 22 (2009) – Published March 16, 2009

Superconductivity

Decoration experiments of the two-gap superconductor MgB₂ show evidence for long-range attraction between vortices in a superconducting mixed state, which is interpreted as coexisting type-I and type-II

C. R. Stroud, Physics 2, 19 (2009) – Published March 9, 2009

Atomic & Molecular Physics

An atomic physics experiment demonstrates a solution to an eighty-year-old quantum conundrum by mimicking in an atom the astronomical problem of a satellite moving in a sun-earth system.

Thomas Philbin, Physics 2, 17 (2009) – Published March 2, 2009

Optics

A proposal for a new type of cloaking device suggests a way to hide both a distant object and the cloak itself.

Paul Mantica, Physics 2, 18 (2009) – Published March 2, 2009

Nuclear Physics

Experiments show that spherical and nonspherical states of a light nucleus near neutron number 28 coexist at the same energy, challenging the usefulness of the notion of stable and persistent “magic numbers.”

H. A. Fertig, Physics 2, 15 (2009) – Published February 23, 2009

Semiconductor Physics Mesoscopics Nanophysics

Measurements of the heat transport at the edges of two-dimensional electron systems appear to provide explanations about the quantum Hall state that have not been forthcoming via charge transport experiments.

Matthew F. Doty, Daniel Gammon, Physics 2, 16 (2009) – Published February 23, 2009

Quantum Information Spintronics

Two theoretical studies reveal how one might achieve electric-field control of spin in semiconductors, both in an impurity-localized electron, and also with a quantum dot molecule.

José María De Teresa, Physics 2, 13 (2009) – Published February 17, 2009

Magnetism Spintronics

Using a double spin-filter tunnel junction consisting of two magnetic insulating layers, researchers have observed a sizeable magnetoresistance without using magnetic electrodes, thus tuning the tunneling via the magnetic state of the insulating layers and by application of an electric voltage.

Gary A. Williams, Physics 2, 14 (2009) – Published February 17, 2009

Superfluidity Mesoscopics

Imaging and tracking of bubbles in liquid helium formed by individual electrons allows study of superfluid vortices, and may permit analysis of unusual ionic species in fluids.

Robert McMichael, Mark Stiles, Physics 2, 11 (2009) – Published February 9, 2009

Spintronics

A magnetic domain wall moving along a ferromagnetic wire can generate a voltage across the wire. This electromotive force, which is not the same as Faraday’s law of induction, is part of a growing family of interactions that are being discovered in the field of spintronics.