Magnetic Flux Quantum Teleportation Without a Magnetic Field ✦
Imagine a magnetic 'ghost' jumping between two distant superconducting rings without crossing the space between them. Scientists suspect this eerie leap could test whether quantum effects have boundaries—and maybe even rattle our understanding of reality. Could this ghost unveil the hidden rules of the quantum realm?
Magnetic fields act at a distance. But David Bohm showed that in the quantum world there is a vector potential — an invisible ledger that influences charges even where there is no field. This Aharonov–Bohm effect allows quantum information transfer without direct contact. John Bardeen proposed using it to shuttle a magnetic flux quantum between two superconducting rings.
In the experiment, the rings are connected by a shared loop where a coherent cloud of electrons forces the total flux to be strictly defined. Quantum superposition lets the flux “leap” from one ring to another, much like rewriting a ledger entry transfers money between safes. The leaps are detected by ultrasensitive interferometers — SQUID-based sensors.
If the leap were faster than light, causality would be broken. But quantum decoherence — the loss of coherence as the system grows — most likely prevents this. Roger Penrose predicted that with increasing mass the wave function collapses on its own. The very mechanism that enables teleportation also sets a limit for quantum computers, but in return it offers ultraprecise sensors.
🎯 The magnetic flux quantum is the smallest 'coin' of magnetic field. In a superconducting ring, the current cannot vanish because that would require 'breaking' this coin, and smaller change does not exist. That’s why the ring stores the field forever.