Spin-torque Dynamics for Noise Reduction in Vortex-based Sensors

Abstract

Performance of magnetoresistive sensors is today mainly limited by their 1/f low-frequency noise. Here, we study this noise component in vortex-based TMR sensors. We compare the noise level in different magnetization configurations of the device, i.e vortex state or uniform parallel or antiparallel states. We find that the vortex state is at least an order of magnitude noisier than the uniform states. Nevertheless, by activating the spin-transfer induced dynamics of the vortex configuration, we observe a reduction of the 1/f noise, close to the values measured in the AP state, as the vortex core has a lower probability of pinning into defect sites. Additionally, by driving the dynamics of the vortex core by a non-resonant rf field or current we demonstrate that the 1/f noise can be further decreased. The ability to reduce the 1/f low-frequency noise in vortex-based devices by leveraging their spin-transfer dynamics thus enhances their applicability in the magnetic sensors' landscape.

References in corpus (9)

• Spin torque building blocks
• Vowel recognition with four coupled spin-torque nano-oscillators
• Large microwave generation from d.c. driven magnetic vortex oscillators in magnetic tunnel junctions
• Spin torque resonant vortex core expulsion for an efficient radio-frequency detection scheme
• Probing the Pinning Strength of Magnetic Vortex Cores with sub-nm Resolution
• Optimizing magnetoresistive sensor signal-to-noise via pinning field tuning
• Low offset frequency $1/f$ flicker noise in spin torque vortex oscillators
• Influence of flicker noise and nonlinearity on the frequency spectrum of spin torque nano-oscillators
• Low-frequency and shot noises in CoFeB/MgO/CoFeB magnetic tunneling junctions

Cited by in corpus (4)

• Non-hermiticity in spintronics: oscillation death in coupled spintronic nano-oscillators through emerging exceptional points
• 1/f noise of a tiny tunnel magnetoresistance sensor originated from a wide distribution of bath correlation time
• Control of vortex chirality in a symmetric ferromagnetic ring using ferromagnetic nanoelement
• Low-Noise Nanoscale Vortex Sensor for Out-of-Plane Magnetic Field Detection