Laser Reveals Hidden Magnetism in Everyday Metals

The world of technology is rapidly advancing, with researchers making discoveries every day. Just last week, scientists published their work, which cracked an old physics mystery.

Conducted by researchers from the Hebrew University in collaboration with Pennsylvania State University and the University of Manchester, the study detected subtle magnetic signals in metals that are not normally magnetic, using only light and a modified laser method.

These faint magnetic effects, which are more like “whispers”, in non-magnetic materials have been previously undetectable for obvious reasons; they were just too small. But now, that’s changed. These effects are measurable, disclosing new patterns of electron behavior that were hidden until this study.

With this discovery, scientists have completely transformed how we investigate magnetism in everyday materials, without wires or bulky instruments. This could even open avenues into memory storage, quantum computing, and smaller, faster, and more advanced electronics.

Unraveling the Subtle Magnetic Response in ‘Quiet’ Metals

Published in the journal Nature Communications¹, the study details a new way to identify tiny magnetic signals in metals like gold (Au), copper (Cu), aluminum (Al), tantalum (Ta), and platinum (Pt).

The thing is, we have long known that electric currents bend in a magnetic field, which is the Hall effect. This effect is particularly strong and well-known in magnetic materials like iron, but when it comes to common, non-magnetic metals like gold, the effect is rather weak.

The optical Hall effect (OHE), a related phenomenon, should help visualize the behavior of electrons when light and magnetic fields interact. 

But that’s in theory, as at visible wavelengths, the OHE effect is far too subtle for scientists to detect. So, while we know that the effect is there, we lack the tools to actually measure it.

“It was like trying to hear a whisper in a noisy room for decades. Everyone knew the whisper was there, but we didn’t have a microphone sensitive enough to hear it.”

– Professor Amir Capua from the Institute of Electrical Engineering and Applied Physics at Hebrew University

As Prof. Capua explained, these metals, like copper and gold, are thought to be “magnetically ‘quiet’”. For instance, these materials, gold and copper, do not stick to the fridge like iron does. “But in reality, under the right conditions, they do respond to magnetic fields—just in extremely subtle ways,” he added. And it has always been a challenge to observe these faint effects.

So, in collaboration with other universities, the researchers went on to investigate just how to detect these really small magnetic effects in materials that aren’t magnetic. 

For this, they turned to a technique called magneto-optical Kerr effect (MOKE) and upgraded it. Under the MOKE method, a laser is used to measure how magnetism affects the direction of the light.

The study notes that, because the anomalous Hall effect (AHE) observed in ferromagnets (materials like iron, nickel, or cobalt with long-range, parallel alignment of atomic moments resulting in spontaneous net magnetization) is much stronger than the ordinary Hall effect (OHE), the optical Hall effect is much weaker than the magneto-optical Kerr effect (MOKE). It is so weak that it can hardly be detected in visible light.

Hence, the reason for altering the MOKE technique. The researchers presented the MOKE technique, which is based on the large-amplitude modulation of the externally applied magnetic field. For this, they used permanent magnets placed on a rotating disc.

The researchers combined this with a 440 nm blue laser, which allowed them to significantly boost the sensitivity of the technique. As a result, they were able to detect the magnetic “echoes” in non-magnetic metals, which was previously just about impossible to achieve. The study noted:

“The superior sensitivity of the technique paves the way towards discovery of new phenomena and applications such as an optical determination of the spin-orbit interaction.” 

Optical Echo Reveals Hidden Magnetic Signals in Metals

Hall measurements are a key technique in material research and solid-state physics. The Hall effect allows us to study materials at the atomic scale and find out just how many electrons are in a metal. It is crucial in bridging the gap between fundamental research and practical applications.

However, measuring the effect is traditionally a tricky and time-consuming process, especially when working with components that are really small, on the nanometer scale. For this, scientists have to first attach wires to the device, but not anymore.

The new approach is very simple; it only needs a laser to be shone on the electrical device.

As Prof. Capua noted, even Edwin Hall, who discovered the Hall effect, had no success when he tried to measure the effect using a beam of light. As Hall summarized in the closing sentence of his paper back in 1881:

“I think that, if the action of silver had been one tenth as strong as that of iron, the effect would have been detected. No such effect was observed.” 

But in the latest research, the scientists have, in fact, observed the effect “by tuning in to the right frequency—and knowing where to look,” said Prof. Capua. 

With that, the team has “found a way to measure what was once thought invisible,” Prof. Capua added, “This research turns a nearly 150-year-old scientific problem into a new opportunity.”

Looking even deeper helped the team find that what seemed to be a random ‘noise’ in their signal wasn’t so random after all, but had a clear meaning and pattern. 

The pattern followed was related to spin-orbit coupling (SOC). This quantum property connects how electrons move to how they spin, which affects the way magnetic energy dissipates in materials. 

The new insights gained have direct and significant implications for designing spintronic devices, magnetic memory, and quantum systems.

“It’s like discovering that static on a radio isn’t just interference—it’s someone whispering valuable information. We’re now using light to ‘listen’ to these hidden messages from electrons.”

– Ph.D. candidate Nadav Am Shalom from the Hebrew University

The novel technique actually offers a non-invasive, highly sensitive tool for exploring magnetism in metals, without requiring massive magnets or cryogenic conditions. 

The simplicity and precision of the technique could also help engineers build more energy-efficient systems, faster processors, and sensors with strong accuracy.

But this is all just the beginning, with the study talking about broadening the spectrum of materials in future work. This includes additional metals, multi-layered films, semiconductors, and topological and 2D materials. 

Also, a “temperature-dependent measurement is of particular interest, as it could offer key insight into the noise mechanisms and underpin a deeper understanding of their origin,” stated the study.

Click here to learn how lasers can turn non magnetic materials into magnetic.

Expanding the Hall Effect with New Possibilities

Over the past year, researchers have continued to look into Hall effect techniques, pushing the boundaries of what’s possible. Building on classic electrical Hall measurements, scientists are uncovering new regimes, signaling a transformative shift. 

This includes the discovery² of significant nonlinear Hall effects (NLHE) at room temperature in tellurium (Te). The effect is a second-order response to an applied alternating current (AC) that generates second-harmonic signals without needing an external magnetic field. 

NLHE, a new member of the Hall effect family, has been getting a lot of attention because of its possible usage in frequency-doubling and rectifying devices. Challenges like low working temperatures and low hall voltage outputs, however, have limited its practical applications. 

So, a research team from the University of Science and Technology of China (USTC) of the Chinese Academy of Sciences (CAS) searched for systems that show remarkable NLHE in semiconductor materials. They then looked into the nonlinear response of tellurium, a brittle and rare element that has a one-dimensional helical chain. Its structure inherently lacks inversion symmetry, which makes Te the perfect candidate.

When they put thin flakes of tellurium (Te) to the test, they discovered considerable nonlinear Hall effects at room temperature. At a temperature of 300 K, the maximum second-harmonic output meanwhile can go an order of magnitude higher than previous records, as high as 2.8 mV.

Upon a deeper dive, the NLHE observed in the thin flakes of tellurium was found to be mainly the result of extrinsic scattering. Here, the breaking of the structure’s surface symmetry played a crucial role.

Based on that, the AC current was replaced by radiofrequency (RF) signals that realized wireless RF rectification in Te thin flakes and achieved stable rectified voltage output over a range of 0.3 to 4.5 GHz. This way, the study opens up new possibilities for the development of advanced electronic devices.

Recently, researchers from the University of New South Wales focused on the bulk states of topological insulators, Bi2Se3 and Sb2Te3, and found³ that the orbital Hall torque dominates the spin Hall torque for an efficient conversion of charge current to spin current.

The bulk states give rise to a sizable OHE, up to 3 orders of magnitude larger than the SHE, in topological insulators, in part due to the orbital angular momentum of each conduction electron being larger than its spin. 

It also noted that optimizing the orbital to spin conversion in TI (topological insulators) spin torque devices is key to having more efficient control over magnetization, but that will require advanced techniques and specific ferromagnets. 

Meanwhile, researchers from Johannes Gutenberg University showed⁴ an efficient use of the enhanced orbital Hall conductivity of Cr, Nb, and Ru layers along with a perpendicularly magnetized ferromagnetic layer for Spin-Orbit Torque (SOT) Magnetic Random-Access Memory (MRAM) devices. 

SOT-MRAM devices promise better performance, nonvolatility, and power efficiency compared to static RAM. To achieve long data retention and efficient magnetization switching in these devices, we need ferromagnets with perpendicular magnetic anisotropy (PMA) combined with large torques increased by Orbital Hall Effect (OHE). 

So, the team designed a PMA (Co/Ni)3 FM on selected OHE layers and investigated the potential of orbital Hall conductivity (OHC).

The results show a 30% improvement in torque efficiency and a 60% reduction in switching power, highlighting the “promising potential of leveraging the enhanced orbital Hall effect to propel the performance of next-generation of SOT MRAM devices for high-density packed cache memory applications.”

Investing in Spintronics Tech

Everspin Technologies (MRAM -2.22%) actively uses electron spin rather than charge to store data. It is a leading developer of magnetoresistive random access memory (MRAM) solutions, a type of non-volatile RAM that stores data in magnetic domains.

MRAM uses an electron spin’s magnetism to provide non-volatility and stores information in magnetic material integrated with silicon circuitry to deliver the non-volatility of Flash and the speed of SRAM in one device. 

Its MRAM technology products include Toggle MRAM, which provides a simple, high-density memory with Everspin using a patented Toggle cell design to offer high reliability. Its other product is Spin-transfer Torque MRAM (STT-MRAM), which uses the manipulation of electrons’ spin with a polarizing current to establish the desired magnetic state of MTJ.

Everspin Technologies (MRAM -2.22%)

With a market cap of $150 million, MRAM shares are currently trading at $6.68, up 4.54% YTD. Its EPS (TTM) is -0.01, and the P/E (TTM) is -451.35.

For the first quarter ended March 31, 2025, the company reported total revenue of $13.1 million. Its MRAM product sales, including both Toggle and STT-MRAM revenue, meanwhile, were $11 million. Revenue from licensing, royalties, patents, and others was $2.1 million.

During this period, the gross margin was 51.4%, GAAP operating expenses were $8.7 million, GAAP net loss was $1.2 million or $(0.05) per diluted share, and non-GAAP net income was $0.4 million or $0.02 per diluted share.

Cash and cash equivalents at the end of the quarter increased to $42.2 million.

This year, Everspin also secured a contract from Purdue University to utilize its MRAM as the underpinning in a program called CHEETA (CMOS+MRAM Hardware for Energy Efficient AI). Its PERSYST MRAM, meanwhile, got validated for configuration across all Lattice Semiconductor FPGAs.

Earlier this year, the company announced two new products as part of its Orion xSPI family, featuring an automotive temperature range for persistent, high-speed memory requirements in extreme environments. 

“We expect our existing and new customers to deploy Everspin’s robust MRAM products and technology in such mission critical applications through design wins and Strategic Radiation Hard programs for memory and FPGA applications.” 

– Aggarwal

Latest Everspin Technologies (MRAM) Stock News and Developments

Conclusion

With each new study, researchers uncover what scientists couldn’t for years. The latest one does exactly that by turning the faint optical signals into a clear magnetic presence, creating a new way for non‑invasive electron spin probing. Moreover, they have revealed that what once appeared as noise actually encodes rich spin‑orbit information and that can potentially transform spintronic design, magnetic memory, and quantum technologies, leading to more energy-efficient devices and enhanced data storage capacity.

Click here to learn how Ni₄W memory breakthrough will enable magnet-free switching.

References:

1. Am-Shalom, N.; Rothschild, A.; Bernstein, N.; Ginzburg, N.; Vinnicombe, H.; Illg, C.; Földes, D.; Kolel-Veetil, M.; Alfrey, A.; Bromley, S. T.; Barbiellini, B.; Everschor-Sitte, K.; Mishra, S.; Haim, M.; Lifshitz, E.; Hamann, D. R.; Stiles, M. D.; Schecter, M.; Sztenkiel, D.; Kapitulnik, A. A Sensitive MOKE and Optical Hall Effect Technique at Visible Wavelengths: Insights into the Gilbert Damping. Nature Communications, 16, 6423 (2025). Published online July 17, 2025. https://doi.org/10.1038/s41467-025-61249-4
2. Cheng, B.; Gao, Y.; Zheng, Z.; Wang, K.; Liu, X.; Li, Z.; Wang, G.; Liu, Y.; Huang, J.; Lai, J.; Xu, C.; Zhang, Y.; Zhao, Y.; Wang, J.; Lin, X.; Xu, X.; Lu, H.; Xu, Y. Giant Nonlinear Hall and Wireless Rectification Effects at Room Temperature in the Elemental Semiconductor Tellurium. Nature Communications, 15, 5513 (2024). Published online June 29, 2024. https://doi.org/10.1038/s41467-024-49706-y
3. Cullen, J. H.; Liu, H.; Culcer, D. Giant orbital Hall effect due to the bulk states of 3D topological insulators. npj Spintronics, 3, 22 (2025). Published online June 3, 2025. https://doi.org/10.1038/s44306-025-00087-y
4. Gupta, R.; Bouard, C.; Kammerbauer, F.; Shin, H.; Tang, P.; Shukla, N.; Kundu, A.; Sinn, S.; Finizio, S.; Heidler, J.; López-Díaz, L.; Kläui, M.; Jakob, G.; Kronast, F.; Jungfleisch, M. B.; Beens, M.; Garg, C.; Parkin, S. S. P. Harnessing Orbital Hall Effect in Spin-Orbit Torque MRAM. Nature Communications, 16, 130 (2025). Published online January 2, 2025. https://doi.org/10.1038/s41467-024-55437-x