The coupling between a primordial magnetic field and the cosmic axion field generates a helical component of the magnetic field around the time in which the axion starts to oscillate. If the energy density of the seed magnetic field is comparable to the energy density of the universe at that time, then the resulting magnetic helicity is about |HB| ≃ (10 G) kpc and remains constant after its gen...

We present a study of a carotenoid-porphyrin-fullerene triad previously shown to function as a chemical compass: the photogenerated carotenoid-fullerene radical pair recombines at a rate sensitive to the orientation of an applied magnetic field. To characterize the system we develop a time-resolved Low-Frequency Reaction Yield Detected Magnetic Resonance (tr-LF-RYDMR) technique; the effect of v...

Abstract. The magnetic moment of an electron gas on the surface of constant negative curvature is investigated. It is shown that the surface curvature leads to the appearance of the region of the monotonic dependence M(B) at low magnetic fields. At high magnetic fields, the dependence of the magnetic moment on a magnetic field is the oscillating one. The effect of the surface curvature is to in...

A unique experimental system with collisionless electrons has been developed to investigate waveparticle interaction and/or particle acceleration in turbulence. In the system, electrons are injected from a tip of electron source along a magnetic field in a region between two electrostatic potentials. Some of the electrons trapped in the potentials are accelerated and other electrons are deceler...

We present a detailed numerical study of a microscopic artificial swimmer realized recently by Dreyfus in experiments [Dreyfus, Nature 437, 862 (2005)]. It consists of an elastic filament composed of superparamagnetic particles that are linked together by DNA strands. Attached to a load particle, the resulting swimmer is actuated by an oscillating external magnetic field so that it performs a n...