S. Petit, N. de Mestier, C. Baraduc, C. Thirion, B. Diény
We showed for the first time that the widely studied “spin transfer torque” phenomenon presents a measurable effect below the critical threshold. In the sub-critical regime, the transfer of momentum from the conduction electrons to the magnetisation fluctuations results in a surprising dependence of the magnetic noise upon the sign of the bias current. Remarkably, the spin transfer can be used to quench the thermally activated magnetization fluctuations. A precise de- scription of this effect was achieved by developing an analytical model to analyse our experimental data.