Professors Erez Hasman of the Technion – Israel Institute of Technology and Bo Wang of Shanghai Jiao Tong University, along with their colleagues, have discovered the emergence of photon “swirling” within disordered nanometric systems. This breakthrough, detailed in Nature Materials, demonstrates a “spin locking effect induced by Brownian motion” – enabling the detection of spin-order in physically disordered systems. The researchers achieved this by illuminating nanometric particles suspended in liquid at room temperature, observing that scattered photons exhibited locked spin due to the particles’ random Brownian motion. This previously unknown phenomenon reveals information about particle size and material type, potentially impacting nanoparticle characterization and the development of new optical technologies.
Discovery of Photon “Swirling” in Disordered Systems
Researchers at the Technion – Israel Institute of Technology and Shanghai Jiao Tong University discovered photon “swirling,” specifically a “spin-locking effect,” within disordered nanometric systems. This breakthrough challenges the previous belief that Brownian motion causes chaotic photon scattering. Instead, the team found that photons scattered sideways from nanometric particles in liquid became “locked” in their spin due to the particles’ random movement – a phenomenon observed at room temperature when illuminated with laser light.
The discovery centers on a new physical phenomenon termed “spin locking effect induced by Brownian motion.” This indicates that order can emerge even in systems disordered in both space and time. Prior to this research, Brownian motion was thought to result in unpolarized and incoherent photon scattering, but the team demonstrated that specific light-matter interaction conditions can lead to spin order in the scattered photons.
This “spin-locking effect” isn’t merely a scientific curiosity; it also offers a novel method for particle characterization. The strength of the spin-locking effect correlates with both the size and material type of the nanoparticles, enabling researchers to measure these properties. Prof. Hasman suggests potential applications range from nanoparticle characterization to developing new optical technologies, signifying a significant contribution to both science and industry.
The Spin-Locking Effect and Brownian Motion
Researchers at the Technion and Shanghai Jiao Tong University discovered a new physical phenomenon called the “spin-locking effect induced by Brownian motion.” This effect enables the detection of spin-order even within physically disordered systems. The team found that when laser light interacts with nanometric particles in a liquid, photons scattered sideways become “locked” in their spin – a surprising result considering Brownian motion was previously thought to cause chaotic photon scattering.
This spin-locking effect arises because of the particles’ random movement – their Brownian motion, also known as a “drunkard’s walk.” Einstein famously described this phenomenon in 1905. Contrary to previous beliefs, the researchers demonstrated that this randomness doesn’t simply lead to chaotic scattering; instead, it can induce order in the spin of scattered photons under specific light-matter interaction conditions.
Importantly, the degree of spin-locking depends on both the size and material type of the particles. This connection allows researchers to measure particle characteristics using this effect. Prof. Hasman notes that this discovery highlights the importance of experimental physics, showing that deep order can emerge even within the most disordered systems, potentially leading to new optical technologies and improved nanoparticle characterization.
Until now, it was believed that Brownian motion causes the scattering of photons off particles to be chaotic – that is, unpolarized and incoherent – and so too the spin of the scattered photons.
Technion Research News and Recognition
Researchers at the Technion, led by Prof. Erez Hasman, discovered a new physical phenomenon called the “spin locking effect induced by Brownian motion.” Published in Nature Materials, the study demonstrated that photons scattered from nanometric particles undergoing random Brownian motion exhibit locked spin. This challenges the previous belief that Brownian motion causes chaotic photon scattering, revealing that order can emerge even in disordered systems. The findings could contribute to advancements in nanoparticle characterization and new optical technologies.
Recognition of Technion faculty is also highlighted, with Prof. Hossam Haick elected as a Fellow of the National Academy of Inventors on December 14, 2025. Additionally, Dr. Yakir Vizel received a prestigious European ERC Consolidator Grant on December 9, 2025, signifying the high level of research being conducted at the institute.
The Technion’s academic standing was further affirmed by the Shanghai Ranking of Academic Subjects 2025, placing the university among the top 100 worldwide in six specific fields. This ranking, alongside the individual recognitions of Haick and Vizel, showcases the Technion’s continued commitment to impactful research and innovation, building on the recent discovery of spin-locking in disordered systems.
