Chaotic Dynamics of Spin-Valve Oscillators

TL;DR

This paper predicts intrinsic chaotic behavior in spin-valve oscillators driven by electric currents, revealing complex bifurcation sequences and distinct power spectra, advancing understanding of magnetization dynamics.

Contribution

It introduces the prediction of intrinsic chaos in spin-valve oscillators and details the transition via period doubling bifurcations, which was not previously known.

Findings

Chaotic dynamics occur in spin-valve oscillators.

Transition to chaos involves period doubling bifurcations.

Two distinct power spectra are identified in the chaotic regime.

Abstract

Recent experimental and theoretical studies on the magnetization dynamics driven by an electric current have uncovered a number of unprecedented rich dynamic phenomena. We predict an intrinsic chaotic dynamics that has not been previously anticipated. We explicitly show that the transition to chaotic dynamics occurs through a series of period doubling bifurcations. In chaotic regime, two dramatically different power spectra, one with a well-defined peak and the other with a broadly distributed noise, are identified and explained.