A local wormhole is a physical system characterized by the no-cloning of information that mediates the action of an exchange-free quantum computer: locally induced spatial entanglements of a single particle, and corresponding self-interference scenarios allow entangling other degrees of freedom among spatially separated parties, without any particle observably crossing – rendering space disjunctly traversabile.
Hatim Salih proposes an experimental realisation of the protocol for the counterfactual disembodied transport of an unknown qubit — or what they call counterportation — where sender and receiver, remarkably, exchange no particles. Image credit: Genty.
The invention, by University of Bristol physicist Hatim Salih, provides the first-ever practical blueprint for creating in the lab a wormhole that verifiably bridges space, as a probe into the inner workings of the Universe.
By deploying a novel computing scheme, which harnesses the basic laws of physics, a small object can be reconstituted across space without any particles crossing.
Among other things, it provides a ‘smoking gun’ for the existence of a physical reality underpinning our most accurate description of the world.
“This is a milestone we have been working towards for a bunch of years,” Dr. Salih said.
“It provides a theoretical as well as practical framework for exploring afresh enduring puzzles about the Universe, such as the true nature of spacetime.”
The need for detectable information carriers traveling through when we communicate has been a deeply ingrained assumption among scientists, for instance a stream of photons crossing an optical fiber, or through the air, allowing people to read this text.
Or, indeed, the myriad neural signals bouncing around the brain when doing so.
This holds true even for quantum teleportation, which, Star Trek aside, transfers complete information about a small object, allowing it to be reconstituted elsewhere, so it is indistinguishable in any meaningful way from the original, which disintegrates. The latter ensures a fundamental limit preventing perfect copying.
Notably, the recent simulation of a wormhole on Google’s Sycamore processor is essentially a teleportation experiment.
“Here’s the sharp distinction. While counterportation achieves the end goal of teleportation, namely disembodied transport, it remarkably does so without any detectable information carriers travelling across,” Dr. Hatim said.
Wormholes were popularised by the mega-hit movie Interstellar, which included physicist and Nobel laureate Kip Thorne among its crew.
But they first came to light about a century ago as quirky solutions to Einstein’s gravity equation, as shortcuts in the fabric of spacetime.
The defining task of a traversable wormhole, however, can be neatly abstracted as making space traversable disjunctly; in other words, in the absence of any journey across observable space outside the wormhole.
The pioneering research, fittingly completed to Interstellar’s spine-tingling background music, sets out a way to carry this task out.
“If counterportation is to be realised, an entirely new type of quantum computer has to be built: an exchange-free one, where communicating parties exchange no particles,” Dr. Hatim said.
“By contrast to large-scale quantum computers that promise remarkable speed-ups, which no one yet knows how to build, the promise of exchange-free quantum computers of even the smallest scale is to make seemingly impossible tasks — such as counterportation — possible, by incorporating space in a fundamental way alongside time.”
“The goal in the near future is to physically build such a wormwhole in the lab, which can then be used as a testbed for rival physical theories, even ones of quantum gravity,” he said.
His paper was published in the journal Quantum Science and Technology.
Hatim Salih. 2023. From counterportation to local wormholes. Quantum Sci. Technol 8: 025016; doi: 10.1088/2058-9565/ac8ecd
Source : Breaking Science News