Capacitance Enhanced Synchronization of Pairs of Spin-Transfer Oscillators

Macro-spin simulations have been performed to study the synchronization of pairs of serially connected spin torque oscillators in parallel with a capacitor. The sensitivity to the STO process variation, which is modeled by the anisotropy field distribution for different STO samples, can be dramatically decreased by the coupling of a capacitor in the circuit. There exists an optimum capacitance where the multi-STO synchronized state develops the highest robustness.

[1]  Berger Emission of spin waves by a magnetic multilayer traversed by a current. , 1996, Physical review. B, Condensed matter.

[2]  W. Rippard,et al.  Direct-current induced dynamics in Co90 Fe10/Ni80 Fe20 point contacts. , 2003, Physical review letters.

[3]  Yan Zhou,et al.  Perpendicular spin torque promotes synchronization of magnetic tunnel junction based spin torque oscillators , 2009 .

[4]  Johan Åkerman,et al.  Spin torque oscillator frequency versus magnetic field angle: The prospect of operation beyond 65 GHz , 2009 .

[5]  Yan Zhou,et al.  Phase-locked spin torque oscillators : Impact of device variability and time delay , 2007 .

[6]  Understanding the current-induced magnetization dynamics in the presence of large magnetic fields , 2006 .

[7]  A. Slavin,et al.  Current-induced bistability and dynamic range of microwave generation in magnetic nanostructures , 2005 .

[8]  Andrei Slavin,et al.  Theory of mutual phase locking of spin-torque nanosized oscillators , 2006 .

[9]  M. Stiles,et al.  Macrospin models of spin transfer dynamics , 2005, cond-mat/0504142.

[10]  V. Cros,et al.  Synchronization of spin-transfer oscillators driven by stimulated microwave currents , 2005, INTERMAG 2006 - IEEE International Magnetics Conference.

[11]  Yan Zhou,et al.  Intrinsic phase shift between a spin torque oscillator and an alternating current , 2007 .

[12]  B. N. Engel,et al.  Phase-locking in double-point-contact spin-transfer devices , 2005, Nature.

[13]  J. Katine,et al.  Mutual phase-locking of microwave spin torque nano-oscillators , 2005, Nature.

[14]  D. Ralph,et al.  Microwave oscillations of a nanomagnet driven by a spin-polarized current , 2003, Nature.

[15]  J. C. Sloncxewski,et al.  Current-driven excitation of magnetic multilayers , 2003 .

[16]  J. Katine,et al.  Electrical measurement of spin-wave interactions of proximate spin transfer nanooscillators. , 2006, Physical review letters.

[17]  Yan Zhou,et al.  Tunable intrinsic phase of a spin torque oscillator , 2008 .