Long-range effects in layered spin structures

Interface effects in spin-polarized metal/insulator layered structures

Recent advances in thin-film deposition techniques, such as molecular beam epitaxy and pulsed laser deposition, have allowed for the manufacture of heterostructures with nearly atomically abrupt interfaces. Although the bulk properties of the individual heterostructure components may be well-known, often the heterostructures exhibit novel and sometimes unexpected properties due to interface eff...

Spin Waves in Layered Structures of Antiferromagnetic F.C.C. MnTe

Spin waves in antiferromagnetic spin chains with long-range interactions

We study antiferromagnetic spin chains with unfrustrated long-range interactions that decay as power laws with exponent b , using the spin-wave approximation. We find for sufficiently large spin S that the Neel order is stable at T50 for b,3, and survives up to a finite Neel temperature for b,2, validating the spin-wave approach in these regimes. We estimate the critical values of S and T for t...

Occasional ‘‘long-range’’ nonequilibrium body-centered-cubic structures in NiFe/Cu spin valves

We describe conventional and high-resolution transmission electron microscopy ~HRTEM! characterization of the microstructure of sputtered NiFe/Cu giant magnetoresistance spin valves ~Cu/FeMn/NiFe/Cu/NiFe! sandwiched between thick Nb contact layers. Six spin valves, sputtered at different temperatures, three with thin ~3 nm! and three with thick ~24 and 30 nm! NiFe layers, were studied. All of t...

Long-range electron spin-spin interactions from unparticle exchange.

Unparticles as suggested by Georgi are identities that are not constrained by dispersion relations but are governed by their scaling dimension d. Their coupling to particles can result in macroscopic interactions between matter that are generally an inverse nonintegral power of distance. This is totally different from known macroscopic forces. We use the precisely measured long-ranged spin-spin...