Quantum is Different, Part 1

Richard Feynman

Caltech Course : Potentialities and Limitations of Computing Machines “Nature isn't classical, dammit, and if you want to make a simulation of nature, you'd better make it quantum mechanical.”

Persistent current in a superconducting circuit Magnetic field of a single electron Polarization of a single photon Internal state of a single atom

Quantum entanglement Nearly all the information in a typical entangled “quantum book” is encoded in the correlations among the “pages”. You can't access the information if you read the book one page at a time. This Page Blank This Page Blank This Page Blank This Page Blank This Page Blank ….

To describe 300 quantum bits (e.g., atoms), we would need more numbers than the number of atoms in the visible universe!

Quantum Supremacy! ???

David Wineland Krysta Svore

Quantum is Different, Part 2

Richard Feynman

Credit card fraud is a distant memory --- your quantum card can be validated, but it can’t be copied.

Noninvasive quantum sensors, imaging the human brain at the molecular scale, illuminate the foundations of consciousness.

Optical space telescopes, by sharing quantum entanglement, observe an alien on another planet.

Highly efficient solar panels exploiting quantum coherence power the earth.

The world's leading physicists, who have played quantum games since age 3, cannot understand why 20th century physicists thought quantum mechanics is weird.

A quantum computer can simulate efficiently any physical process that occurs in Nature. (Maybe. We don’t actually know for sure.) particle collisionentangled electronsmolecular chemistry black holeearly universe superconductor

( + ) Decoherence Environment ( + )

Environment Decoherence ERROR! To avoid errors, we must prevent the environment from “learning” about the state of the quantum computer during the computation. Quantum Computer

Quantum error correction The protected “logical” quantum information is encoded in a highly entangled state of many physical qubits. The environment can't access this information if it interacts locally with the protected system. This Page Blank This Page Blank This Page Blank This Page Blank This Page Blank …. Environment

Kitaev’s magic trick: sawing an electron in half!

Holographic Principle All information inside the room is encoded, in a scrambled form, on the boundary of the room.

Holographic Principle This scrambled encoding may be a quantum error- correcting code. The emergent space inside the room is robust against errors on the walls of the room.

Holographic Principle Quantum entanglement holds space together.

Deep insights into the quantum structure of spacetime arise from laboratory experiments studying highly entangled quantum systems..