- Using their Sycamore processor, the experimentalists implemented a small-scale version of the SYK model. This is a model that has many interesting properties, including the fact that it is a testbed for holography, in which a bulk system may be understood by the degrees of freedom on its boundary. For an infinitely large SYK system, there is a duality to a 2D gravitational system. So, a protocol for moving entanglement in the qubits that make up the SYK system is equivalent to having a traversable wormhole in that 2D gravitational system.
- The actual experiment is very cool.
- The coverage in the press was extensive (Quanta, NY Times, e.g.). There was a lot of controversy (see Peter Woit's blog for a summary, and Scott Aaronson for a good take) surrounding this, because there was some initial language usage that implied to a lay-person that the team had actually created a traversable wormhole. Quanta revised their headline and qualified their language, to their credit.

- What do we mean when we say that we have experimentally implemented a model of a system? When atomic physicists use ultracold fermionic atoms to make a 2D lattice governed by the Mott-Hubbard model (like here and here), we say that they have made a Mott insulator. That same model is thought to be a good description of copper oxide superconductors. However, no one would say that it actually
*is*a copper oxide superconductor. When is a model of a thing actually the thing itself? This is at the heart of the whole topic of quantum simulation, but the issue comes up in classical systems as well. My two cents: If system A and system B are modeled extremely well by the same mathematics, that can give us real insights, but it doesn't mean that system A*is*system B. Better language might be to say that system A is an analog to system B. Physicists can be sloppy with language, and certainly it is much more attention-getting to editors of all stripes (be they journal editors or journalism editors) to have a short, punchy, bold description. Still, it's better to be careful. - What do theorists like Lenny Susskind truly mean when they claim that entanglement is genuinely equivalent to wormholes? This is summarized by the schematic equation ER = EPR, where ER = Einstein-Rosen wormhole and EPR = Einstein-Podolsky-Rosen entanglement. I think I get the core intellectual idea that, in quantum gravity, spacetime itself may be emergent from underlying degrees of freedom that may be modeled as sorts of qubits; and that one can come up with fascinating thought experiments about what happens when dropping one member of an entangled pair of particles into the event horizon of a black hole. That being said, as an experimentalist, the idea that any kind of quantum entanglement involves actual Planck-scale wormholes just seems bonkers. That would imply that sending a photon through a nonlinear crystal and producing two lower energy entangled photons is actually creating a Planck-scale change in the topology of spacetime. Perhaps someone in the comments can explain this to me. Again, maybe this is me not understanding people who are being imprecise with their word choice.