Relation between switching time distribution and damping constant in magnetic nanostructure.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Nanotechnology

Background:

• Switching time in magnetic nano-structures depends on thermal stability and external factors like magnetic fields or spin currents.
• Accurate measurement of switching time is vital for designing efficient spin-transfer torque magnetic random access memory (STT-MRAM).
• Understanding switching behavior is crucial for advancements in magnetic data storage.

Purpose of the Study:

• To investigate the distribution of switching times in magnetic nano-structures.
• To develop an analytical method for extracting key magnetic parameters from switching time distributions.
• To validate the analytical findings through numerical simulations.

Main Methods:

• Derivation of an analytical expression relating damping constant and anisotropy field to switching time distribution under high energy barrier conditions.
• Numerical solution of the Fokker-Planck equation to confirm the analytical model.
• Experimental measurement of the full width half maximum (FWHM) of the switching time distribution.

Main Results:

• A simple analytical expression was derived for the switching time distribution.
• The damping constant and anisotropy field can be accurately extracted by measuring the FWHM of the switching time distribution.
• The method is applicable to both individual nano-structures and arrays with variations.

Conclusions:

• The FWHM of the switching time distribution provides a direct route to determine damping constant and anisotropy field.
• This technique offers a practical approach for characterizing magnetic nano-structure devices.
• The method's versatility extends to inhomogeneous nano-structure arrays, enhancing its applicability in MRAM development.