Nonvolatile State Configuration of Nano-Watt Parametric ISING Spins Through Ferroelectric Hafnium Zirconium Oxide MEMS Varactors

This work reports on an Ising system formed by two artificial spins and relying, for the first time, on a ferroelectric MEMS device to permanently configure the spins’ interactions to ferromagnetic or anti-ferromagnetic. These spins, consisting of two parametric oscillators (POs) built from off-the-shelf components, are driven by the same 2MHz ("pump") signal and are coupled through a series LC-network with resonance frequency (f
C
) formed by two inductors and a microfabricated hafnium zirconium oxide (HZO) MEMS varactor. We show that leveraging the nonvolatile ferroelectric memory characteristic of the HZO varactor allows a shift of f
C
to a lower or to a higher value than ~1MHz based on HZO polarization state, triggering nonvolatile ferromagnetic or anti-ferromagnetic interactions without consuming power for the spin-coupling during the system operation. These features, together with the exceptionally low power threshold of the POs, makes the reported Ising system consume the least power-per-spin (~600nW) reported to date.