Competing domains in EB nanostrucutres

Manipulation of competing ferromagnetic and antiferromagnetic domains in exchange-biased nanostructures.
Arantxa Fraile Rodríguez, Ali C. Basaran, Rafael Morales, Miroslavna Kovylina, Jordi Llobet, Xavier Borrisé, Matthew A. Marcus, Andreas Scholl, Ivan K. Schuller, Xavier Batlle, and Amílcar Labarta
Phys. Rev. B 92, 174417 (2015)

Fraction of inverted domains for Ni(6nm)/FeF2(70nm) as a function of the AD, measured at zero field and 30 K, upon ZFC from 296 K (red) and FC (black; HFC=50Oe from 200 K to 45 K and HFC=0Oe from 45 K to 30 K). The error bars represent the standard deviation over up to 15 independent measurements. The occasional data points where no error bar is given refer as to cases where a comparable statistics is not available. The dashed lines are guides to the eye.

Stability of skyrmionic bits

Stability of single skyrmionic bits.
J. Hagemeister, N. Romming, K. von Bergmann, E. Y. Vedmedenko & R. Wiesendanger
Nature Communications 6, 8455 (2015)

(a) Triangular spin lattice with a hexagonal boundary shape containing a single skyrmion at k_BT=0.05 J and μB=0.1 J. (b) The inset displays the DM energy as a function of the Monte Carlo step (MCS) for different magnetic field strengths at k_BT=0.61 J exhibiting a two-state behaviour due to the ongoing creation and annihilation of a single skyrmion. The size of the system is such that it contains a maximum of one skyrmion at a given MCS. The histogram of the DM energy shows two peaks corresponding to the FM and Sk states. The Sk and FM states are populated with equal probability at the critical field B_c and the areas underneath the peaks of the histogram are equal.

Inertia in spin dynamics

Spin dynamics with inertia in metallic ferromagnets.

Toru Kikuchi and Gen Tatara

Phys. Rev. B 92, 184410 (2015)

(a) Without any magnetic field, the general motion of spin with finite inertia is a free precession motion, just like a spinning top. The spin Sn precesses around the total angular momentum j0. (b) When a constant magnetic field B is applied, the total angular momentum j0 precesses around B. Therefore the “free precession cone” in (a) precesses around B as a whole, which corresponds to the Larmor precession in the absence of the inertia. What was called the free precession in (a) is now called the nutation.