Sachdev-Ye-Kitaev models and holographic metals

4 problems

• A clean local lattice model with SYK low-energy physics

  Open

  SYK needs random couplings among all particles, which no real material has. It is unknown whether an ordinary non-random lattice with short-range interactions can behave the same way at low temperature.

• Has any device shown a measurable SYK-specific signature

  Contested

  Graphene flakes in strong magnetic fields and other platforms have been proposed to realize SYK physics. One 2024 experiment on graphene dots reported transport consistent with SYK, but no measurement yet isolates a property unique to SYK.

• Minimal coupling density preserving SYK chaos in sparse models

  Open

  Removing most random couplings from SYK makes it easier to simulate on quantum hardware. It is unclear how many couplings can be removed before it stops behaving like a black hole.

• Minimal system size for verifiable traversable-wormhole teleportation

  Contested

  Two coupled copies of the SYK model can teleport a quantum bit in a way that mirrors a signal crossing a wormhole in a dual gravity theory. A 2022 experiment claimed this with a heavily simplified model, and critics argue that model is too small and too regular to support the claim.