Controlling the phase locking of unstable magnetic bits for ultra-low power computation

作者: N. Locatelli , V. Cros , H. Kubota , S. Yuasa , R. Lebrun

DOI:

关键词: Materials scienceSuperparamagnetismComputationThermal energyBeat (acoustics)Periodic functionMagnetizationTopologyPhase lockingNanomagnet

摘要: When fabricating magnetic memories, one of the main challenges is to maintain bit stability while downscaling. Indeed, for volumes a few thousand nm3, energy barrier between configurations becomes comparable thermal at room temperature. Then, switches magnetization spontaneously occur. These volatile, superparamagnetic nanomagnets are generally considered useless. But what if we could use them as low power computational building blocks? Remarkably, they can oscillate without need any external dc drive, and despite their stochastic nature, beat in unison with an periodic signal. Here show that phase locking tunnel junctions be induced suppressed by electrical noise injection. We develop comprehensive model giving conditions synchronization, predict it achieved total cost lower than 10-^13 J. Our results open path ultra-low computation based on controlled synchronization oscillators.

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