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We report a comprehensive small angle neutron scattering study (SANS) of the magnetic phase diagram of the doped semiconductor Fe_{1-x}Co_{x}Si for x=0.2 and 0.25. For magnetic field parallel to the neutron beam we observe a six-fold intensity pattern under field-cooling, which identifies the A-phase of Fe_{1-x}Co_{x}Si as a skyrmion lattice. The regime of the skyrmion lattice is highly hysteretic and extents over a wide temperature range, consistent with the site disorder of the Fe and Co atoms. Our study identifies Fe_{1-x}Co_{x}Si is a second material after MnSi in which a skyrmion lattice forms and establishes that skyrmion lattices may also occur in strongly doped semiconductors.

Spin Control Controlling and manipulating the spin of an electron is a central requirement for applications in spintronics. Some of the challenges researchers are facing include efficient creation of spin currents, minimization of Joule heating, and extending the lifetime of electronic spins, which is especially important for quantum information applications. Costache and Valenzuela (p. 1645 ) address the first challenge by designing and fabricating an efficient and simple superconducting-based single-electron transistor that can produce spin current with controlled flow. Key to the design is asymmetric tunneling, which leads to a ratchet effect (or diode-like behavior), allowing the separation of up and down spins. Jonietz et al. (p. 1648 ) use electric currents five orders of magnitude smaller than those used previously in nanostructures to manipulate magnetization in a bulk material, MnSi, pointing the way toward decreased Joule heating in spintronic devices. This so-called spin-torque effect causes the rotation of the skyrmion lattice of spins, characteristic of MnSi, which is detected by neutron scattering. Finally, McCamey et al. (p. 1652 ) extend the short lifetime of an electronic spin of a phosphorous dopant by mapping it onto the much longer lived nuclear spin of the atom. Mapping the nuclear spin back onto the electronic spin allows production of a spin memory with a storage time exceeding 100s, which should prove useful for future practical applications.