Jerusalem Physicists Discover Novel Woven Structure for Ultra-Reliable Photonic Memory

Scientists at the Hebrew University of Jerusalem, in collaboration with colleagues, have discovered a novel "woven" structure within a crystal that could form the basis for ultra-reliable optical memory. Unlike conventional memory, which stores information in discrete, vulnerable cells, this new approach utilizes a unique ordering within a transparent potassium-lithium tantalate-niobate crystal. Researchers observed that when this crystal is slowly cooled to just below room temperature, the regions storing information interlace into a three-dimensional network, resembling a woven fabric where "threads" pass over and under each other. This phenomenon, previously unseen in solid crystals, was observed in crystals grown by Dr. Aaron Agranat of the Hebrew University, initially intended for optical switches. The interwoven structure provides significant stability, protecting the charged boundaries between information-holding regions from random disturbances. While robust against noise and defects, the pattern can be intentionally altered. A focused green laser can locally "unravel" the weave without affecting the rest of the crystal. Subsequent heating and cooling cycles can re-establish the weave, but with a new pattern each time. This discovery paves the way for a new type of photonic memory where information is stored in the overall interwoven pattern, rather than individual cells. This pattern is resistant to noise and defects, and can be read and rewritten using light, making it suitable for optical computing and brain-mimicking neuromorphic systems. The researchers noted that this is the first demonstration of a woven structure spontaneously forming within a solid crystal, suggesting nature's inventiveness surpasses current theories. They also speculate that similar structures might exist in liquid crystals and superconductors, awaiting further discovery.