Imagine a world where Newton's laws are defied, and the very foundations of physics are challenged. Researchers from Japan have unveiled a groundbreaking discovery that does just that! They've developed a theoretical framework that predicts a mind-bending phenomenon: non-reciprocal interactions in solids that defy Newton's third law of motion. But how is this possible?
The secret lies in the power of light. By shining a carefully tuned light onto a magnetic metal, the researchers discovered they could induce a torque, causing two magnetic layers to engage in a mesmerizing 'chase-and-run' rotation. This phenomenon, they argue, opens up a whole new realm of non-equilibrium materials science.
In the natural world, physical systems are governed by the law of action and reaction, ensuring equilibrium. But in non-equilibrium systems, such as biological entities or active matter, non-reciprocal interactions are not uncommon. Think of the brain, where inhibitory and excitatory neurons interact asymmetrically, or the predator-prey relationship, which is inherently non-reciprocal. And now, the researchers have found a way to bring this concept to solid-state electronic systems.
The team, led by Associate Professor Ryo Hanai, proposed a method to induce these non-reciprocal interactions using light. They demonstrated that by selectively activating decay channels in magnetic metals, they could create an energy imbalance between spins, resulting in non-reciprocal magnetic interactions. This is where it gets fascinating: they applied this technique to a bilayer ferromagnetic system, triggering a non-equilibrium phase transition. One magnetic layer tries to align, while the other resists, creating a chiral phase with persistent chase-and-run dynamics.
This chiral phase transition is a direct consequence of broken action-reaction symmetry, and the researchers believe it could have far-reaching implications. They suggest that this discovery not only offers a new way to control quantum materials with light but also connects the dots between active matter and condensed matter physics. And the potential applications are vast, from Mott insulating phases to superconductivity and even new spintronic devices.
But here's where it gets controversial: is it truly possible to violate Newton's laws? The researchers argue that their work effectively challenges this fundamental principle. This bold claim is sure to spark debate among scientists and enthusiasts alike. What do you think? Are we witnessing a paradigm shift in our understanding of physics, or is there another explanation for these intriguing findings?
