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.
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.
New results from the Fermi Gamma-Ray Space Telescope, the most precise to date in the energy range to , 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.
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.
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. Ab initio calculations that can now better reconcile theory with experiment are poised to make such accurate predictions about new materials, it may not even be necessary to grow them.
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.
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.
Physics2, 24 (2009) – Published March 30, 2009
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.
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.
Decoration experiments of the two-gap superconductor show evidence for long-range attraction between vortices in a superconducting mixed state, which is interpreted as coexisting type-I and type-II superconductivity.
Physics2, 21 (2009) – Published March 16, 2009
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.