Chinese scientists discover a new peculiar quantum state of matter – Interesting Engineering

For the last 20 years, scientists have been trying to discover counterflow superfluidity in quantum systems.2 days ago2 days ago2 days ago2 days ago2 days ago2 days ago2 days ago2 days ago2 days ago2 days ago3 hours ago6 hours ago6 hours ago6 hours ago7 hours ago7 hours ago9 hours ago9 hours ago9 hours ago11 hours agoRupendra BrahambhattThis breakthrough could lead to new quantum technologies. (Representational image)Jian Fan/iStockResearchers from the Chinese Academy of Sciences have experimentally demonstrated counterflow superfluidity (CSF) for the first time.It is an exotic quantum state where two components (for example, different types of atoms or spins) flow in opposite directions with perfect correlation. Despite both components being superfluid, the system as a whole remains stationary and incompressible.According to the researchers, CSF will be an important tool for studying and simulating complex quantum systems in ultracold environments, especially for exploring new quantum phases and spin-related phenomena.Counterflow superfluidity is not a new concept; scientists have known about this quantum phase for the last two decades. It is actually an extension of the findings from the Bose-Hubbard model, a theoretical model proposed in 1963 to explain the behavior of bosons in a lattice system. Some other mathematical models also theorize CSF, but until now, scientists couldn’t observe this phase in an experimental setup due to several technical challenges.“Realizing and identifying this phase experimentally has proven challenging due to the stringent requirements for a single setup, including defect-free state preparation, minimal heating during coherent manipulations, and spin- and site-resolved detection of the phases,” the study authors explain. To achieve the secret CSF phase, the researchers prepared a two-component system using ultracold rubidium-87 atoms with two different spin states. The atoms were then placed in a grid of laser light, which trapped the atoms in specific positions. This resulted in the formation of a spin Mott insulator, a fascinating material that, in theory, is supposed to conduct electricity but, in reality, doesn’t. This is because the strong interactions between the spins of its particles cause them to become localized, preventing the electrons from moving freely.By adjusting the interaction between atoms in this system at one nanokelvin temperature (-273.15°C or -459.67°F), the researchers shifted from a ‘frozen’ state (spin-Mott insulator) to one where the two types of atoms flowed in opposite directions while remaining perfectly balanced, demonstrating counterflow superfluidity.To confirm whether the system has truly entered the CSF phase, the study authors used a quantum gas microscope — a highly advanced imaging tool that allows scientists to view individual atoms within a lattice.They measured the correlations between the different positions (and spins) of the atoms and found antipair correlations, i.e., the existence of atoms in opposite states.“Antipair correlations, the hallmark of the CSF, were corroborated by the measurements in both real and momentum spaces under a quantum gas microscope,” the study authors note.This observation confirmed that when one atom moved in one direction, another atom in the opposite spin state moved in the opposite direction. Additionally, the researchers observed long-range correlations in the spin states, with the system maintaining coherence across the entire lattice—another strong indicator of the CSF phase.The discovery of superfluidity in 1930 led to the development of many exciting low-cold technologies, such as laser cooling. Hopefully, CSF will also pave the path for many groundbreaking quantum applications.The study is published in the journal Nature Physics. Stay up-to-date on engineering, tech, space, and science news with The Blueprint.By clicking sign up, you confirm that you accept this site’s Terms of Use and Privacy PolicyRupendra Brahambhatt Rupendra Brahambhatt is an experienced writer, researcher, journalist, and filmmaker. With a B.Sc (Hons.) in Science and PGJMC in Mass Communications, he has been actively working with some of the most innovative brands, news agencies, digital magazines, documentary filmmakers, and nonprofits from different parts of the globe. As an author, he works with a vision to bring forward the right information and encourage a constructive mindset among the masses.a day agoa day agoa day agoa day agoPremiumIE PROFollow

Source: https://interestingengineering.com/science/counterflow-superfluidity-in-quantum-systems