At the purest frontiers of science and operating on a nanometric scale, a research team led by Prof. Erez Hasman at the Faculty of Mechanical Engineering has created a photonic “Big Bang” in laboratory conditions.
The multidisciplinary team demonstrated the transition from an orderly physical system to a disorderly system in optics on a nano-scale. The nanooptics Big Bang occurs when there is increased disorder and the system reaches a critical point of disorder, meaning dispersal of the opposite spinning photons in every direction. “Our research deals with the development of nanometer scale optical devices and with understanding the interaction between light and tiny structures,” explains Prof. Hasman, head of the nano-optics lab.
The photonic “Big Bang” used nanometric metasurfaces based on tiny silicone antennas (nano-antennas). “Using nano-antennas that we produced in the lab using silicone technology, we developed a method to control disorder in the system – increasing the entropy,” elaborates Prof. Hasman. “Light is composed of photons, massless particles, travelling in a speed of light. Each photon behaves like a spinning top that spins either clockwise or counter-clockwise.”
A “photonic spin Hall effect” occurs when an orderly state is transformed into a state of minor disorder, meaning that the angle of the nano-antennas is slightly altered. This effect is a spatial separation between photons spinning in opposite directions; photons with positive spins move in a certain direction and others with negative spins move in the opposite direction.
The research, published in Science, provides inspiration for understanding disorder in solid states, and will impact the field of spintronics. Furthermore, it opens opportunities for designing artificial materials while controlling their level of disorder.