Dancing Synchronization in Coupled Spin-Torque Nano-Oscillators

TL;DR

This paper introduces 'dancing synchronization,' a novel dynamic phase relationship between coupled spin-torque nano-oscillators, characterized by periodic phase variation and potential for new device functionalities.

Contribution

It reports the discovery of dancing synchronization in coupled STNOs, a new dynamic state differing from traditional phase-locked synchronization, and demonstrates its universality in nonlinear oscillators.

Findings

Dancing synchronization involves periodic phase variation.

It depends on coupling strength and driven currents.

It is universal across different nonlinear oscillator models.

Abstract

We are reporting a new type of synchronization, termed dancing synchronization, between two spin-torque nano-oscillators (STNOs) coupled through spin waves. Different from the known synchronizations in which two STNOs are locked with various fixed relative phases, in this new synchronized state two STNOs have the same frequency, but their relative phase varies periodically within the common period, resulting in a dynamic waving pattern. The amplitude of the oscillating relative phase depends on the coupling strength of two STNOs, as well as the driven currents. The dancing synchronization turns out to be universal, and can exist in two nonlinear Van der Pol oscillators coupled both reactively and dissipativly. Our findings open doors for new functional STNO-based devices.