Dielectric Magnetic Recording via Photomagnetic Switching

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Solution Overview

Problem

Current magnetic recording technologies rely on thermal mechanisms in metallic materials, which limit speed and efficiency, and have not demonstrated all-optical switching in dielectric materials without external magnetic fields.

Innovation Solution

A dielectric magnetic recording medium with anisotropic ions and high Gilbert damping, excited by ultrafast laser pulses to induce nonthermal photomagnetic effects, allowing magnetization switching without external magnetic fields or heating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If thermal mechanism is used in metallic materials for magnetic recording, then magnetization switching can be achieved, but recording speed and energy efficiency are limited

Engineering Contradiction:

Improverecording speedVSAvoidenergy efficiency

Core Design Contradiction:

SpeedVSUse of energy by moving object

Solution Approach 1:

The patent replaces the thermal mechanism (heating to Curie temperature) with a non-thermal photomagnetic mechanism. Ultrafast laser pulses induce direct magnetization switching through photomagnetic effects in dielectric materials, eliminating the need for thermal heating and enabling much faster recording speeds while reducing energy consumption.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the fundamental mechanism parameter from thermal to non-thermal. By using dielectric materials with specific photomagnetic properties and applying ultrafast laser pulses, the system achieves magnetization switching without temperature increase, thereby improving both speed and energy efficiency.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If strong laser-induced heating is applied to switch magnetization in metallic systems, then magnetization switching is achieved, but heat load and energy consumption increase

Engineering Contradiction:

Improvemagnetization switchingVSAvoidheat load

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent substitutes the thermal heating mechanism with a direct photomagnetic switching mechanism. By using dielectric materials that exhibit non-thermal photomagnetic effects, the system achieves reliable magnetization switching without generating significant heat, thereby eliminating the energy loss associated with heating to Curie temperature.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Use of energy by moving object

If all-optical switching is implemented in dielectric materials, then energy efficiency improves, but external magnetic fields are typically required

Engineering Contradiction:

Improveenergy efficiencyVSAvoidrequirement for external magnetic field

Core Design Contradiction:

Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent enables the dielectric material to switch its own magnetization using only optical pulses, without requiring external magnetic fields. The photomagnetic effect in the dielectric material directly induces magnetization switching, making the system self-sufficient and eliminating the need for additional magnetic field generation components.

Inventive Principle:

Principle #25Self-service

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables ultrafast and energy-efficient all-optical magnetization switching with negligible heat load, overcoming speed and energy consumption limitations in existing technologies.

Implementation Method 1

illuminating said dielectric magnetic layer by a light pulses that have a pulse duration equal to not more than 100 ps; tuning a wavelength and a polarization of the light pulses to cause optical resonances excitation of said anisotropic ions, thereby inducing transitions to the excited states of said anisotropic ions

Methodology Applied

Scientific EffectPhotomagnetic effect: Magneto-Optic Effects

Implementation Method 2

the dielectric magnetic layer comprising anisotropic ions having a difference in a single ion contribution to magnetic anisotropy (ΔK/ion) between a ground state and an excited state of said anisotropic ions equal to at least 0.1 cm−1 (0.0124 meV/ion) at 20° C. (68° F.)

Methodology Applied

Scientific EffectMagnetic anisotropy: Anisotropy

Implementation Method 3

wherein the effective Gilbert damping (α) of said dielectric magnetic layer is equal to at least 0.01

Methodology Applied

Scientific EffectGilbert damping: Damping

Data Source

PatentUS10037777B1Ultrafast photomagnetic recording in a dielectric medium using anisotropic ions effective gilber damping

Publication Date: 2018.07.31 UNIV W BIAYMSTOKU

AI summary

A recording medium comprising a dielectric magnetic layer, the dielectric magnetic layer comprising anisotropic ions having a difference in a single ion contribution to magnetic anisotropy (ΔK/ion) between a ground state and an excited state of said anisotropic ions equal to at least 0.1 cm−1 (0.0124 meV/ion) at 20° C. (68° F.), wherein the effective Gilbert damping (α) of said dielectric magnetic layer is equal to at least 0.01.