Memory-bit selective recording in vortex-core cross-point architecture

In our earlier work [Appl. Phys. Lett. 92, 022509 (2008)], we proposed nonvolatile vortex random access memory (VRAM) based on the energetically stable twofold ground state of vortex-core magnetizations as information carrier. Here we experimentally demonstrate reliable memory bit selection and low-power-consumption recording in a two-by-two vortex-state dot array. The bit selection and core switching is made by flowing currents along two orthogonal addressing electrode lines chosen among the other crossed electrodes. Tailored pulse-type rotating magnetic fields are used for efficiently switching a vortex core only at the intersection of the two orthogonal electrodes. This robust mechanism provides reliable bit selection and information writing operations in a potential VRAM device.

[1]  J. Kortright,et al.  Vector magnetization imaging in ferromagnetic thin films using soft x-rays , 2001 .

[2]  R. Hertel,et al.  Ultrafast nanomagnetic toggle switching of vortex cores. , 2007, Physical review letters.

[3]  Young-Sang Yu,et al.  Low-Power Selective Control of Ultrafast Vortex-Core Switching by Circularly Rotating Magnetic Fields: Circular–Rotational Eigenmodes , 2008, IEEE Transactions on Magnetics.

[4]  Young-Sang Yu,et al.  Universal criterion and phase diagram for switching a magnetic vortex core in soft magnetic nanodots. , 2008, Physical review letters.

[5]  Konstantin Yu. Guslienko,et al.  Stability of magnetic vortex in soft magnetic nano-sized circular cylinder , 2002 .

[6]  R. Wiesendanger,et al.  Direct Observation of Internal Spin Structure of Magnetic Vortex Cores , 2002, Science.

[7]  E. Anderson,et al.  Soft X-ray microscopy of nanomagnetism , 2006 .

[8]  Ki-Suk Lee,et al.  Two circular-rotational eigenmodes and their giant resonance asymmetry in vortex gyrotropic motions in soft magnetic nanodots , 2008 .

[9]  K. Guslienko,et al.  Ultrafast vortex-core reversal dynamics in ferromagnetic nanodots , 2007, cond-mat/0703538.

[10]  C. H. Back,et al.  Magnetic vortex core reversal by excitation with short bursts of an alternating field , 2006, Nature.

[11]  Jörg Raabe,et al.  Magnetization pattern of ferromagnetic nanodisks , 2000 .

[12]  A. Fert,et al.  The emergence of spin electronics in data storage. , 2007, Nature materials.

[13]  K. Guslienko,et al.  Electric-current-driven vortex-core reversal in soft magnetic nanodots , 2007 .

[14]  Teruo Ono,et al.  Electrical switching of the vortex core in a magnetic disk. , 2007, Nature materials.

[15]  J. Miltat,et al.  Vortex Cores--Smaller Than Small , 2002, Science.

[16]  Ono,et al.  Magnetic vortex core observation in circular dots of permalloy , 2000, Science.

[17]  Arne Vansteenkiste,et al.  Vortex core switching by coherent excitation with single in-plane magnetic field pulses. , 2008, Physical review letters.

[18]  Russell P Cowburn,et al.  Spintronics. Change of direction. , 2007, Nature materials.

[19]  Young-Sang Yu,et al.  Reliable low-power control of ultrafast vortex-core switching with the selectivity in an array of vortex states by in-plane circular-rotational magnetic fields and spin-polarized currents , 2008 .