2021-10-04

Light quantum fluid reveals the wave state of strange matter in condensed matter physics

By yqqlm yqqlm

Light quantum fluid reveals the wave state of strange matter in condensed matter physics </ P >

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p > in a strong light matter coupling system, the excitation of electrons in a semiconductor placed between two mirrors will be strongly affected by photons trapped in it. This leads to a new quantum mode called exciton polaron, or polaron for short. They enable people to study the mixing phenomenon of matter wave and photon on the micro scale. Under appropriate conditions, the polariton can form a coherent multi-body matter state similar to Bose Einstein condensate, which provides an opportunity to study the singular dissipative nonlinear dynamics</ p>

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p > the researchers decided to explore how these condensates behave in artificial optical lattices that do not usually exist in nature. To this end, they used a programmable spatial light modulator to shape the laser beam into a lattice in the cavity, which is different from the laser indicator cap used to project fancy patterns on distant surfaces. Where the laser field is strongest, the number of poles produced increases and the energy is greater. At sufficiently high laser power, polaritons begin to form condensates, which reside at the maximum potential energy of the lattice. In this so-called “ballistic” system, the high-energy polarized wavelet escaping from the condensate is scattered and diffracted in the lattice</ p>

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p > researchers observed that when the lattice constant decreased, the condensate experienced a phase transition from the ballistic system to the opposite situation, that is, the deeply trapped condensate was reflected in the potential barrier living in the lattice. At the intermediate lattice constant, the system seems unable to “determine” whether the polarization wavelet should be delocalized or local. On the contrary, the condensate breaks under a variety of energies. Such a transition has never been observed in a polarizer lattice before</ p>

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p > the researchers also proved that they can produce one of the strangest features in solid-state physics – completely colorless and scattered crystal bands, also known as flat bands – where the particle mass actually becomes infinite. To this end, they designed an optical Lieb lattice, which is not common in nature. It is known to have flat bands</ p>

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p > the research in this report was co written by young researchers in the hybrid photonics laboratory led by Professor Pavlos lagoudakis. He made the following comments on the team’s findings. “Our laboratory already has a good expertise in the optical lattice of polarizer condensates, and we have taken another step forward through this work. These results will arouse the interest of a wide range of scientific communities, including nonlinear optics, condensed matter physics, cold atoms, light matter physics and polaritons. This is the first time to display matter in optically generated polarizer lattices The first author of the paper, Dr. Sergey alyatkin, an experimental physicist from skoltech, and his colleagues, Dr. helgi sigurdsson, a theoretical physicist from Southampton University, added: “Our work has very well proved the progress of optical control and the richness of polarizer field. The more we study the microcavity polaritons in the lattice, the more interesting effects we observe. Our latest achievements have opened up an unexplored path in physics for the unsteady lattice mixture of matter wave quasiparticles, and we are not limited to the specific types of lattices studied. “