Black Holes, Quantum Entanglement and the No-Go Theorem

Sun, 04 Jul 2021 07:00:00 GMT
Scientific American - Science

New research shows that there are problems even quantum computers might never be able to solve

Now suppose her nemesis, Bob, has a quantum computer that's entangled with the black hole.

QUANTUM COMPUTERS TO STUDY QUANTUM MECHANICS. Alice might never have the chance to hide her secrets in a black hole.

Still, our new no-go theorem about information scrambling has real-world application to understanding random and chaotic systems in the rapidly expanding fields of quantum machine learning, quantum thermodynamics, and quantum information science.

Richard Feynman, one of the great physicists of the 20th century, launched the field of quantum computing in a 1981 speech, when he proposed developing quantum computers as the natural platform to simulate quantum systems.

The research sheds light on what sorts of algorithms will do real work on existing noisy, intermediate-scale quantum computers and on unresolved questions in quantum mechanics at large.

ENTANGLEMENT LEADS TO SCRAMBLING. We wondered if we could apply quantum machine learning to understand scrambling.

As the entanglement among particles within the quantum system grows, the information spreads widely; this scrambling of information is key to understanding quantum chaos, quantum information science, random circuits and a range of other topics.

By exploring it with a variational quantum algorithm on a theoretical quantum computer entangled with the black hole, we could probe the scalability and applicability of quantum machine learning.

The good news is, most physical processes are not as complex as black holes, and we often will have prior knowledge of their dynamics, so the no-go theorem doesn't condemn quantum machine learning.

We're not likely to need quantum machine learning to peer inside a black hole to learn about Alice's book-or anything else-anytime soon.