Can you imagine a river of light? Water gushing from broken lamps with the appearance of golden light? Well, this fantasy, although almost out of fiction, is surprisingly close to a reality that science has already begun to unravel: the possibility that light behaves “almost” like a liquid. In laboratories around the world, scientists have shown that, under certain conditions, light can flow much like a river, a phenomenon that is opening new frontiers between physics and technology.
WHAT IS LIQUID LIGHT?
Liquid light is a fascinating phenomenon that combines the properties of light with the characteristics of fluids. Imagine a special type of matter in which particles move together in perfect harmony, just as if they were one. This is known as Bose-Einstein condensate (BEC). Typically, these condensates are created with gas atoms at extremely low temperatures. However, scientists have figured out how to make them with light particles.
The magic of liquid light is found in special particles called polaritons, which have the ability to behave like liquids under certain conditions. So, to create liquid light, scientists place very thin materials between super-reflective mirrors and bombard them with extremely short laser pulses. In this way, they achieve the photons couple and move in harmony with the rest, forming a condensate of polaritons, also called liquid light.
However, the most surprising thing about liquid light is its ability to flow without resistance. Unlike normal liquids, which create waves and swirls due to friction, liquid light moves without losing energy or facing obstacles. This behavior is similar to that of superfluidswhere the particles move in an orderly and synchronized manner.
The flow of polaritons encounters an obstacle in non-superfluid states (top), but not in superfluid states (bottom).
A PATH TO DISCOVERY
Without a doubt, the discovery of liquid light is the result of decades of research in quantum physics and optics. It all began with the study of Bose-Einstein condensates in the 1920s, by Albert Einstein and Satyendra Nath Bose, a state in which particles are cooled to temperatures close to absolute zero. However, the greatest advance towards liquid light occurred in 2017, when a team led by Daniele Sanvitto, from the CNR NANOTEC Nanotechnology Institute in Italy, managed to produce liquid light at room temperatureand. This was possible thanks to the use of an ultrathin film of organic molecules between two highly reflective mirrors, which was bombarded with very very short laser pulses.
Thus, the creation of polaritons under these conditions allowed the photons to behave like a superfluidflowing no friction or viscosity. This was undoubtedly a revolutionary advance, as it demonstrated that superfluidity, a property that until then had only been observed in extremely cold fluids such as liquid helium, was also possible in a system of light and matter at accessible temperatures. This discovery opened the door to a wide range of research on the properties of liquid light and its possible technological applications.
This was the first light of the Universe
However, international collaboration has been essential throughout this journey. Various teams from institutions such as the École Polytechnique de Montreal in Canada or Aalto University in Finland have contributed significantly to the understanding of this phenomenon. The experiments and theories developed have provided a comprehension much deeper understanding of how photons can form a quantum fluid and have laid the foundations for future applications in a multitude of fields.
BEYOND THE LABORATORY
Thus, in computing and electronics, liquid light could allow the development of optical computers, much faster and more efficient than current ones. By utilizing the properties of superfluidity, these devices could transmit information without energy loss and without the excessive heating that limits the performance of conventional electronic systems. This technology would not only increase processing speed, but also significantly reduce power consumption, paving the way for the development of more powerful devices. sustainable and ecological.
Furthermore, in the field of telecommunications and the photonics, liquid light could transform the way we transmit and process data. Communication systems based on liquid light could offer much greater and much faster information transmission capacity, without the power dissipation problems faced by current technologies. Also, the ability of polaritons to move without friction could improve the efficiency and flexibility of the optical devicesallowing the development of flexible and holographic displays as well as advanced sensors for medical and chemical detection applications.
