Spin-wave excitations: the main source of the temperature dependence of interlayer exchange coupling in nanostructures.

Quantum mechanical calculations based on an extended Heisenberg model are compared with ferromagnetic resonance experiments on prototype trilayer systems Ni(7)/Cu(n)/Co(2)/Cu(001) in order to determine and separate for the first time quantitatively the sources of the temperature dependence of interlayer exchange coupling. Magnon excitations are responsible for about 75% of the reduction of the coupling strength from zero to room temperature. The remaining 25% are due to temperature effects in the effective quantum well and the spacer-magnet interfaces.

Behavioral stochastic resonance: how a noisy army betrays its outpost.

Juvenile paddlefish prey upon single zooplankton by detecting a weak electric signature resulting from its feeding and swimming motions. Moreover, it has recently been shown that paddlefish make use of stochastic resonance near the threshold for prey detection: a process termed behavioral stochastic resonance. But this process depends upon an external source of electric noise.