キラルスピントロニクスがコンピューティングを変革する方法

スピントロニクスがコンピューティングを革命的に変える方法

Progressively, the world of hardware computing is starting to look beyond silicon chips, or even classical forms of binary computing altogether.

これは、コンピュータやデータセンターで使用される従来のチップとメモリがますます製造が困難になっており、最新世代のトランジスタはわずか数ナノメートルのサイズにまで縮小しているためです。

もう一つの要因は、特にAIシステム向けの計算能力需要が増大する中で、エネルギー消費が問題となっていることです。

提案されている解決策は多数あり、量子コンピューティングやフォトニクスが、計算需要を削減したり、より高速でエネルギー効率の高い計算を実現する代表的な選択肢です。

Another is spintronics, which utilizes the spin of electrons, a quantum characteristic, instead of the electric current (the flow of electrons).

スピントロニクスの利点と潜在的応用

Electronic components, such as transistors, are traditionally built from silicon and rely on semiconductors. The 0 and 1 signals in binary indicate the passing or blocking of an electric current.

計算を実行する代替手段として、電流（電子の流れ）ではなく電子のスピン（基本的な量子特性）を利用するスピントロニックデバイスがあります。

Source: Insight IAS

データは、電子の「上向き」または「下向き」の方向性としてイメージできるスピン角運動量と、電子が原子核の周りを回る様子を表す軌道角運動量の両方にエンコードできます。

0 と 1 だけに比べて情報量が多いため、スピンは従来のエレクトロニクスよりも原子あたりのデータ容量が大きくなります。

スピントロニクスは従来の電子システムに比べていくつかの利点があります, notably:

• スピンははるかに速く切り替えられるため、データ転送が高速です。
• スピンは電流を維持するために必要なエネルギーよりも少ない電力で切り替えられるため、エネルギー消費が低減します。
• 複雑な半導体材料の代わりに、シンプルな金属を使用できます。
• スピンは半導体の状態よりも揮発性が低く、データ保存がより安定します。

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Spintronics has been commercialized in hard drive read heads since the 1990s, significantly boosting storage density over the past decades.

“Spin is a quantum mechanical property of electrons, which is like a tiny magnet carried by the electrons, pointing up or down.

私たちは電子のスピンを利用して、いわゆるスピントロニクスデバイスで情報の転送と処理を行うことができます。

Talieh Ghiasi – Postdoc Researcher at Delft University of Technology

Much recent progress has been made in spintronics, for example, that spin loss can be converted back into magnetisation, making spintronics electronics even more energy-efficient, or that spintronics & graphene could power next-gen quantum circuits.

そして科学者たちは、ソウル大学（韓国）や韓国大学、韓国科学技術院、米国フェインバーグ医学校の研究者らが、電子スピンを制御できる磁性ナノヘリックスを作り出し、いわゆる「キラルスピントロニクス」デバイスという全く新しい分野を創出する可能性を示しました。

They published their results in the prestigious scientific magazine Science¹, under the title “Spin-selective transport through chiral ferromagnetic nanohelices”.

キラルスピントロニクス

スピントロニクスにおけるキラリティとは何か？

In nature, symmetry is a fundamental feature of many things, including the components of DNA and light itself. It is possible that two molecules almost identical to each other differ not in their composition or shape, but in their orientation, a concept called “chirality”.

キラリティは、最も単純な形では、左手と右手が形状・構造・機能は同一でありながら、向きが異なることとして説明できます。

キラリティは生物学において根本的な役割を果たし、自然選択は「右手系」のDNA分子、糖、アミノ酸（タンパク質の基本構成要素）を選択的に採用してきました。

It is, however, rare in inorganic materials, which tend to either be disorganized or crystals without chirality.

スピントロニクスのために金属がキラリティを獲得する方法

The scientists managed to create both left- and right-handed chiral magnetic nanohelices by electrochemically controlling the metal crystallization process. An alloy of cobalt-iron was chosen for its ferromagnetic properties.

A key innovation in this process is using trace amounts of chiral organic molecules, such as cinchonine or cinchonidine, which guided the formation of the helices.

“In metals and inorganic materials, controlling chirality during synthesis is extremely difficult, especially at the nanoscale.

The fact that we could program the direction of inorganic helices simply by adding chiral molecules is a breakthrough in materials chemistry.”

Pr. Ki Tae Nam – Professor at Seoul National University

To demonstrate the chirality of these nanohelices, they measured electromagnetic fields (EMF) generated by the helices under rotating magnetic fields.

This creates an easy way to test if the material was produced properly, as the left- and right-handed helices produced opposite EMF signals, allowing for quantitative verification of chirality, not requiring the magnetic material to strongly interact with light, the usual way to check for chirality.

More importantly, they discovered that these chiral magnetic metals can also guide the spin accordingly: they preferentially allow one direction of spin to pass, while the opposite spin cannot.

“Chirality is well-understood in organic molecules, where the handedness of a structure often determines its biological or chemical function,”

Pr. Ki Tae Nam – Professor at Seoul National University

キラルスピントロニクスの潜在的応用

Through the material’s inherent magnetization (spin alignment), long-distance spin transport at room temperature became possible.

This effect proved constant, regardless of the angle between the chiral axis and the spin injection direction. As it was not observed in non-magnetic nanohelices of the same scale, it seems to be directly linked to the chiral magnetic helices.

This would make the first-ever discovered asymmetric spin transport in a relatively macro-scaled material.

The team also demonstrated a solid-state device that showed chirality-dependent conduction signals, paving the way for practical spintronic applications.

“These nanohelices achieve spin polarization exceeding ~80% — just by their geometry and magnetism,”

This is a rare combination of structural chirality and intrinsic ferromagnetism, enabling spin filtering at room temperature without complex magnetic circuitry or cryogenics, and provides a new way to engineer electron behavior using structural design.”

Pr. Young Keun Kim – Professor at Korea University

Another advantage of this new technology is that the manufacturing process is relatively simple and cheap, using no rare materials or complex technologies.

“We believe this system could become a platform for chiral spintronics and the architecture of chiral magnetic nanostructures.

This work represents a powerful convergence of geometry, magnetism, and spin transport, built from scalable, inorganic materials.”

Pr. Young Keun Kim – Professor at Korea University

Much more work still needs to be done to fully explore the potential of this new idea and materials. For example, the number of strands (double, multiple helices) can be modified at will, and might yield different characteristics yet to be discovered.

The ability to control the handedness (left/right) and even the number of strands (double, multiple helices) using this versatile electrochemical method is expected to contribute significantly to new application areas.

Pr. Young Keun Kim – Professor at Korea University

Between the ease of production and the possibility of long-distance spin transfer, this could be very useful for the production of fully spin-based computers and networks, with economic advantages from lower energy consumption and stable data storage.

スピントロニックイノベーターへの投資

1. Everspin Technologies

Everspin is a branch of Freescale (now known as NXP, stock ticker NXPI) dedicated to developing MRAM memory systems, the most common form of spintronics that is commercially viable today. It got spun out and went public in 2016.

Everspin は MRAM（磁気抵抗性ランダムアクセスメモリ）技術のリーダーと見なされており、Freescale が 2006 年に世界初の MRAM チップを商業化した経験を継承しています。

Because MRAM is a memory that persists even in the absence of a current, it is increasingly used in sensitive use cases where critical data is too important to risk loss.

データ分析、クラウドコンピューティング（地上・宇宙両方）、人工知能（AI）およびエッジ AI、産業用 IoT などの広範なアプリケーションに支えられ、永続メモリ市場は 2020 年から 2030 年まで年平均成長率 27.5% で拡大すると予測されています。

Everspin

Source: Everspin

The company estimates the market will reach a $7.4B size by 2027. The company has had no debt and positive free cash flow since 2021.

Everspin の MRAM 製品は現在、小規模ながら成長中のニッチ市場を占めており、航空宇宙、衛星、データレコーダー、患者モニタリングデバイスなど、信頼性が重要視される市場で使用されています。

Source: Everspin

The growth of chipsets, AI, and synaptic systems might also be a long-term boost for the company.

2. NVE Corporation

Another leader of spintronics, NVE has been working on this technology since its first patent in MRAM technology in 1995. It produces spintronic sensors and isolators, mostly used in measurement and sensor systems for cars, gears, medical devices, power supplies, and other industrial devices.

Source: NVE

This puts NVE in a somewhat different category than Everspin, with NVE more of an industrial company with a strong position in a niche market (magnetometer using spintronics), while Everspin is more of a memory/computing company working with and in competition with the likes of Intel (INTC ), Qualcomm (QCOM ), Toshiba, and Samsung, who are also developing their own MRAM product.

It can make the stock more (or less) attractive depending on investors’ profiles, with NVE’s stock more likely to appeal to more conservative investors seeking a dividend yield and safety.

参照研究

^{1. Yoo Sang Jeon, et al. Spin-selective transport through chiral ferromagnetic nanohelices. Science. 4 Sep 2025. Vol 389, Issue 6764. pp. 1031-1036. DOI: 10.1126/science.adx5963}