Optical Switch Element Using t2g Orbitals Above Néel Temperature

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Solution Overview

Problem

Magneto-optical switches utilizing the inverse Faraday effect are limited to temperatures below the Néel temperature due to the requirement of long-range magnetic order, which is typically low in magnetic substances.

Innovation Solution

An optical switch element using transition metal elements with d-orbitals and anions arranged in a lattice form, operating without long-range magnetic order, where control light induces polarization rotation through electron transfer among t2g-orbitals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If magneto-optical switch utilizes inverse Faraday effect with long-range magnetic order, then polarization rotation is achieved, but operational temperature is limited below Néel temperature

Engineering Contradiction:

Improveoperational temperature rangeVSAvoidmagnetic order requirement

Core Design Contradiction:

TemperatureVSAdaptability or versatility

Solution Approach 1:

The invention changes the fundamental operating mechanism from relying on long-range magnetic order (inverse Faraday effect) to utilizing orbital motion of electrons in t2g-orbitals. This parameter change in the physical mechanism allows the system to operate above the Néel temperature where magnetic order is lost, thereby expanding the operational temperature range while maintaining polarization rotation capability

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention substitutes the magnetic order-based mechanism with an orbital motion-based mechanism. Instead of utilizing the magnetic properties of ordered sublattices, the system uses the orbital movement of electrons excited by circularly polarized light in the t2g-orbitals of transition metal elements, replacing a magnetic field-dependent mechanism with an optically-driven orbital mechanism that functions at higher temperatures

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Stability of the object's composition

If magnetic substance has low Néel temperature, then material stability is maintained, but operational temperature range is restricted

Engineering Contradiction:

Improvemagnetic order stabilityVSAvoidoperational temperature range

Core Design Contradiction:

Stability of the object's compositionVSTemperature

Solution Approach 1:

The invention extracts the polarization rotation capability from the magnetic order context and relocates it to the orbital motion context. By taking out the dependency on magnetic order and implementing the effect through orbital motion of electrons in t2g-orbitals, the system achieves polarization rotation without requiring stable magnetic order, thus enabling operation above the Néel temperature

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention inverts the conventional approach by not relying on the absence of magnetic order above Néel temperature, but rather by utilizing a different physical mechanism (orbital motion) that is actually enhanced or enabled in the paramagnetic phase. This inversion of the operational principle allows the system to function where conventional magneto-optical switches fail

Inventive Principle:

Principle #13The other way round (Inversion)

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 optical switching operations at temperatures above the Néel temperature, facilitating high-speed communications and operations in optical computers and communication systems.

Implementation Method 1

orbital movement of electrons excited by circular polarized light, through the spin-orbit interaction, results in apparent magnetization in the substance

Methodology Applied

Scientific EffectSpin-orbit interaction:

Implementation Method 2

polarization of signal light is rotated when control light is applied

Methodology Applied

Scientific EffectPolarization rotation:

Data Source

PatentUS12631912B2Optical switch element, optical switch device, optical communication system, and optical computer

Publication Date: 2026.05.19 TOHOKU UNIV

AI summary

An object of the present invention is to provide an optical switch element, an optical switch device, an optical communication system, and an optical computer capable of operating even in a temperature range higher than the Néel temperature. An optical switch element (10) according to the present invention includes a substance including a plurality of transition metal elements having electrons in d-orbitals, and a plurality of anions arranged around each of the plurality of transition metal elements, in which the plurality of transition metal elements are arranged in a lattice form, t2g-orbitals into which the d-orbitals of each of the plurality of transition metal elements are split are connected annularly, and in a state in which the substance does not have a long-range magnetic order, the polarization of signal light (L1) is rotated when control light (C1) is applied.