Our group has recently demonstrated three distinct types of microrobots of progressively smaller size that are wirelessly powered and controlled by magnetic fields. For larger scale microrobots, from 1mm to 500 μm, we microassemble three dimensional devices that precisely respond to torques and forces generated by magnetic fields and field gradients. In the 500 μm to 200 μm range, we have devel...

A primary challenge in the field of reconfigurable robotics is scaling down the size of individual robotic modules. We present a novel set of permanent magnet modules that are 900 μm × 900 μm × 270 μm in size, called Mag-μMods, for use in a reconfigurable micro-system. The module is actuated by oscillating external magnetic fields less than 5 mT in strength, and is capable of locomoting on a 2-...

When ultralight axion dark matter encounters a static magnetic field, it sources an effective electric current that follows the magnetic field lines and oscillates at the axion Compton frequency. We propose a new experiment to detect this axion effective current. In the presence of axion dark matter, a large toroidal magnet will act like an oscillating current ring, whose induced magnetic flux ...

Nuclear Magnetic Resonance serves as an important technique in many fields, including medicine (where it is known as MRI), chemical spectroscopy, and even quantum computation research. At its most basic, NMR is about the coherent manipulation and observation of nuclear dipole moments. Our work here deals exclusively with the hydrogen nucleus, which, being merely one proton, is both the simplest...

We demonstrate the first real-space recording of nanoscale dynamic interactions using single-shot soft x-ray (SXR) full-field laser microscopy. A sequence of real-space flash images acquired with a table-top SXR laser was used to capture the motion of a rapidly oscillating magnetic nanoprobe. Changes of 30 nm in the oscillation amplitude were detected when the nanoprobe was made to interact wit...

Solar prominences are cool 10(4) kelvin plasma clouds supported in the surrounding 10(6) kelvin coronal plasma by as-yet-undetermined mechanisms. Observations from Hinode show fine-scale threadlike structures oscillating in the plane of the sky with periods of several minutes. We suggest that these represent Alfvén waves propagating on coronal magnetic field lines and that these may play a role...

Disorder, or entropy, in a microscopic quantum system has been measured by an international group of physicists. The team hopes that the feat will shed light on the "arrow of time": the observation that time always marches towards the future. The experiment involved continually flipping the spin of carbon atoms with an oscillating magnetic field and links the emergence of the arrow of time to q...

The envelope oscillations of a cold-fluid corkscrewing elliptic beam in a uniformfocusing magnetic field are studied. In particular, by linearizing the generalized beam envelope equations, the eigenmodes of small-amplitude envelope oscillations are calculated for a cold-fluid corkscrewing elliptic beam oscillating about its equilibrium. All of the eigenmodes are shown to be stable. PACS: 29.27....

Many quasars and active galactic nuclei (AGN) appear in radio, optical , and X-ray maps, as a bright nuclear sources from which emerge single or double long, thin jets (Thomson et al., 1993). When observed with high angular resolution these jets show structure with bright knots separated by relatively dark regions. High percentages of polarization, sometimes more then 50% in some objects, indic...

the entanglement at zero-temperature is studied in a two-qubit xz spin-1/2 chain model in anexternal magnetic field which is applied in the z direction. we have obtained an analytical relation forthe effect of the external magnetic field on the concurrence. it is shown that the ground state of thesystem depends on the strength of exchange coupling. we have shown that the analytical relation oft...