Science NewsCurated by RSF Research Staff Home > Science News > A stream of superfluid light Scientists have combined light with electrons to make a room-temperature superfluid. A superfluid is a kind of fifth-state of matter -- a macroscopic quantum state in which the coupling of matter is so strong it no longer consists of separate individual quanta but instead merges into a single indivisible waveform. Superfluids have some remarkable characteristics, for instance they flow with no friction and no viscosity, such that if a superfluid is made to rotate, it will continue to rotate indefinitely. Such a state is often attributed to the vacuum, in superfluid models of space. Physicists Nassim Haramein and Elizabeth Rauscher applied this kind of fluid-dynamic property of space to extend Einstein's field equations to include torque and Coriolis forces. The resulting Haramein-Rauscher solution explains the origin of spin and a superfluid manifold of space. Superfluid behavior is strongly dependent on the specific spin of the interacting particles. Whole-integer spin particles like photons are easily able to overlap and form a unified waveform, which is what laser light is. Other such quanta, which like photons are called bosons, can similarly share the same quantum state, and when this is done -- usually at temperatures a few nanokelvins above absolute zero -- a Bose-Einstein condensate is formed, in which particles behave as a single macroscopic wave all oscillating at the same frequency. Half-integer spin particles, like electrons, cannot share the same quantum state and therefore there is a kind of repulsive force (Pauli pressure) that prevents them from overlapping. However, if two electrons pair up, they add to a whole-integer spin (Cooper pairs) and they can now behave like Bose-Einstein particles. The formation of Cooper pairs requires the many-body interactions of numerous electrons, like what is found in certain materials that can become superconductive (usually only at cryogenic temperatures), where electrical currents are conducted without any diminishment over time or distance. Superconductivity is therefore simply superfluidity of charged electron pairs. Stéphane Kéna-Cohen, the coordinator of the research team that achieved room-temperature superfluidity, states: "To achieve superfluidity at room temperature, we sandwiched an ultrathin film of organic molecules between two highly reflective mirrors. Light interacts very strongly with the molecules as it bounces back and forth between the mirrors and this allowed us to form the hybrid light-matter fluid. In this way, we can combine the properties of photons such as their light effective mass and fast velocity, with strong interactions due to the electrons within the molecules. Under normal conditions, a fluid ripples and whirls around anything that interferes with its flow. In a superfluid, this turbulence is suppressed around obstacles, causing the flow to continue on its way unaltered". "The fact that such an effect is observed under ambient conditions", says the research team, "can spark an enormous amount of future work, not only to study fundamental phenomena related to Bose-Einstein condensates with table-top experiments, but also to conceive and design future photonic superfluid-based devices where losses are completely suppressed and new unexpected phenomena can be exploited". This result paves the way not only for tabletop studies of quantum hydrodynamics, but also for room-temperature polariton devices that can be robustly protected from scattering -- a condition that may be invaluable for photonic-based computations in quantum and optical computers. Article: https://phys.org/news/2017-06-stream-superfluid.html#jCp Quantum physics working at macroscopic scaleDecember 9, 2018A nanophotonic structure used to entangle photosynthetic bacteriaDecember 7, 2018The force of the VacuumDecember 5, 2018Unusual Seismic Phenomenon heard around the WorldDecember 5, 2018An approach to manipulate small objects with lightNovember 30, 2018 Sharing is caring - please share this with your friends: Facebook Twitter If you like this content, you will love the Resonance Academy.