Superluminal correlations in ensembles of optical phase singularities | Nature
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Phase singularities—points carrying quantized topological charge—are universal features found across diverse wave systems from superfluids and superconductors to acoustic and optical fields1–4. Ensembles of these singularities exhibit distance correlations resembling particles in liquids5–8, extensively studied for their role in exotic material phases9–11. By contrast, the full correlations in phase space that govern the system evolution have remained unexplored and experimentally inaccessible. Here we directly measure the ultrafast dynamics of optical singularity ensembles, capturing their full phase-space correlations, presenting the joint distance–velocity distribution. Our observations show a breakdown of the particle-singularity analogy12: phase singularities accelerate towards formally divergent velocities in the moment before annihilation7,13,14, indicated by measurements of velocities exceeding the speed of light. These apparent superluminal velocities are paradoxically amplified by the slow group velocity of hyperbolic phonon polaritons in our material platform, hexagonal boron nitride membranes15–19. We demonstrate these phenomena using combined hardware and algorithmic advances in ultrafast electron microscopy18,20–25, achieving spatial and temporal resolutions, each an order of magnitude below the polaritonic wavelength and cycle period. Our findings deepen our understanding of phase singularities and their universality, enabling to probe topological defect dynamics at previously unattainable timescales. Ultrafast electron imaging shows full phase-space dynamics of optical singularities, which can reach superluminal velocities before annihilation and break the particle-like analogy of topological defects.

Physicists have observed “holes” in light, known as optical vortices, moving faster than the light itself. This phenomenon does not break relativity as the vortices carry no mass, energy, or information. The achievement is a result of using electron microscopy to capture the motion of optical vortices in a two-dimensional material called hexagonal boron nitride.

Key points about the discovery:

  • Optical vortices are whirlpools in a wave of light that can outrun the light they’re embedded within
  • The vortices carry no mass, energy, or information, so they don’t break relativity
  • The phenomenon was observed in a two-dimensional material using a specialized high-speed electron microscope
  • The technique used can help study hidden processes in physics, chemistry, and biology
  • The researchers used a new method called electron interferometry to enhance image sharpness and capture the motion of the vortices.
  • The experiment showed that the vortices can reach superluminal speeds as they approach and annihilate each other.
  • The discovery provides a powerful technological tool for mapping the motion of delicate nanoscale phenomena in materials.
  • melsaskca@lemmy.ca
    1·
    6 hours ago

    Wouldn’t the darkness inside the light’s speed be relative to the light itself? Think of that example of the person walking back and forth on a moving train while an observer outside watches the train pass by.

  • NoWay@lemmy.world
    1·
    6 hours ago

    Doesn’t the position, speed and vector of two vortices count as information? And here I thought that annihilation indicated mass and/or energy.

    Finally, do the light vortices have their own speed constant that it cannot break?

  • clb92@feddit.dkEnglish
    22·
    1 day ago

    Light thinks it travels faster than anything but it is wrong. No matter how fast light travels, it finds the darkness has always got there first, and is waiting for it.

    Terry Pratchett, Reaper Man (Discworld #11)

  • finallymadeanaccount@lemmy.worldEnglish
    7·
    1 day ago

    This reminds me of It Was Nothing - Really by Theodore Sturgeon about the little spaces in perforations between toilet paper being discovered to be indestructible. It went on to make industries out of the ‘nothing’. In real life, could these vortices be used to propel us faster than light?

    Probably not, but it’s fun to think about.