Browse Physics

Published October 6, 2008

Optics

Spatial maps of the photon energy emitted by plasmons on a metal surface reveal standing wave patterns caused by electron confinement.

Hendrick L. Bethlem, Physics 1, 25 (2008) – Published September 29, 2008

Atomic & Molecular Physics

Paramagnetic atoms and molecules experience a force in a magnetic field and scientists have now used this force to decelerate and trap hydrogen atoms. This method promises new opportunities for precision measurements on hydrogen isotopes and may be applied to a host of atoms and molecules for which existing cooling techniques fail.

Published September 29, 2008

Soft Matter

High-intensity x-ray measurements show how suspended particles in a narrow channel are attracted to—or repelled from—the channel walls depending on the ionic concentration of the suspension. These results could have implications for the design of nanofluidic devices.

Published September 29, 2008

Optics

Coupled semiconductor lasers can be used to generate controllable soliton emission patterns.

Published September 29, 2008

Nuclear Physics

Various models in nuclear physics can be used to fit the masses of known nuclei, but the predictions tend to be inconsistent for masses that have not been measured. A thorough study examines this problem and provides a route to quantify these errors.

Simon Cornish, Physics 1, 24 (2008) – Published September 25, 2008

Atomic & Molecular Physics

Atoms colliding in a magnetic field can form weakly bound states called Feshbach molecules. These states have now been used in combination with advanced laser techniques to create tightly bound ground-state molecules close to quantum degeneracy.

Norman J. Wagner, Physics 1, 22 (2008) – Published September 22, 2008

Soft Matter

A shear force can melt a colloidal glass, causing it to flow in a highly nonlinear fashion. Physicists have now found a way to put the description of this type of flow on a more formal theoretical footing.

Jeremy L. O’Brien, Physics 1, 23 (2008) – Published September 22, 2008

Quantum Information Optics

Laser beams made up of millions of sharply defined and coherently locked optical frequencies, called optical frequency combs, may provide a way to implement a powerful quantum computer.

Published September 22, 2008

Spintronics

The efficient injection of polarized spins from magnetic materials into semiconductors, a prerequisite for spintronics applications, is a formidable challenge. With ferromagnetic Co₂FeSi it is now possible to achieve a spin injection efficiency of close to 50%.

Published September 22, 2008

Magnetism Optics

Researchers in Japan have identified spin excitations in multiferroics that can be driven by electric fields.

Published September 22, 2008

Atomic & Molecular Physics

Tuning the interactions between ultracold atoms leads to a strongly interacting superfluid with properties more akin to liquid helium than a dilute Bose-Einstein condensate.

Dung-Hai Lee, Physics 1, 19 (2008) – Published September 15, 2008

Superconductivity

Discovering superconductivity above room temperature is a dream for modern science and technology. Now, theorists propose that for certain types of superconductors, contact with a metal layer could greatly increase the transition temperatures of these materials—in some cases by as much as an order of magnitude.

John Pendry, Physics 1, 20 (2008) – Published September 15, 2008

Optics

Thick layers of disordered materials, such as milk or snow, scatter light so that very little of it gets through. Theorists say that a properly designed combination of incident light waves would be almost completely transmitted and we now have experimental proof of this remarkable result.

Michael R. Norman, Physics 1, 21 (2008) – Published September 15, 2008

Superconductivity

A new class of high-temperature superconductors has been discovered in layered iron arsenic compounds. Results in this rapidly moving field may shed light on the still unsolved problem of high-temperature cuprate superconductivity.

Published September 15, 2008

Interdisciplinary Physics

Calculus, group theory, and other mathematical tools are indispensable for understanding physics. Now the tables may be turned in a new approach toward solving a long-standing problem in mathematics.

Published September 15, 2008

Magnetism

Scientists in Japan have discovered a material with magnetically switchable optical dichroism that is four orders of magnitude larger than what has been seen before.

Published September 9, 2008

Atomic & Molecular Physics

Atoms subjected to strong optical fields exhibit splitting of energy levels. The same effect has now been observed when an atom moves through the periodic field of a crystal lattice.

Published September 9, 2008

Nonlinear Dynamics

Shock waves, familiar from hydrodynamics, acoustics, and optics, have been observed in the changing charge state of iron defects in lithium niobate crystals upon application of even a modest voltage across the crystal.

Detlef Lohse, Physics 1, 18 (2008) – Published September 8, 2008

Fluid Dynamics

A novel dimensionless parameter allows prediction of whether dispersed particles in a turbulent flow enhance or attenuate the turbulence.

Published September 8, 2008

Mesoscopics Semiconductor Physics

A new study is looking at how disorder affects the conducting states in a topological insulator—revealing one of many ways these unusual materials are different from conventional insulators.

Published September 8, 2008

Nonlinear Dynamics

Scientists have developed a unifying theory to describe turbulence in two dimensions that could help explain large-scale flow in the earth’s ocean and atmosphere.

Published September 5, 2008

Graphene Semiconductor Physics

Metallic contacts, which are unavoidable in any connection to an experimental measurement, cause asymmetries in the conductance of electrons and holes in graphene.

Mathias Kläui, Physics 1, 17 (2008) – Published September 2, 2008

Magnetism Nanophysics

Most applications based on magnetism are incompatible with domain walls, which interrupt a homogeneous magnetization. Scientists are turning this view around as they discover new ways to use an electric current to manipulate and store information in nanoscale domain walls.

Published September 2, 2008

Atomic & Molecular Physics

When an atom is bombarded with just enough energy to fully ionize it, how do the electrons and nucleus break apart from each other? Experimentalists are now able to study such a four-body breakup by bombarding a helium atom with an electron.

Published September 2, 2008

Biological Physics Interdisciplinary Physics

Given that vaccine supplies are often limited, a quantitative understanding of how the number and frequency of vaccinations can affect the growth rate of disease would be useful. Physicists show that even a small number of randomly vaccinated individuals can exponentially increase the extinction rate of a disease.