How can we grasp what this “feeling” means?
Suppose we want to create a quantum computer simulator on a regular computer—simulations of entanglement and superposition. What do we do? Let’s say we have 10 qubits, so we need to create a program with 10 threads.
We need to simulate the way threads exchange information. When one thread writes to shared memory, does the other have to wait to avoid overwriting? What… wait? For what? Qubits don’t wait; they instantly transmit information to each other thanks to entanglement.
There’s no “race condition” here—the threads’ rat race among themselves about who gets to write or read anything and when. A regular computer always does everything sequentially. There’s no full parallelism here. A classical computer simply simulates parallelism.
In the case of real qubits, they all have shared memory with each other simultaneously. This is a true commune, like on the island of Utopia.
Each qubit feels all the others at the same moment. Also, a bit like in Bitcoin—each node knows all the information about the entire blockchain. In qubits, unlike blockchain, we don’t have redundancy, that is, excess. Entangled qubits are like one organism at that moment.
Let’s take the example of finding an exit in a maze. In classical computers, we release those 10 threads that go through 10 different paths. If one hits a dead end, it starts to backtrack to look for a passage to an undiscovered path.
This is a simulation of this search. Don’t be fooled; someone probably poorly understands quantum search, but you can watch a bad example too:
Now let’s see how 10 entangled qubits do it. They feel each other. If one qubit hits a dead end, the others already know about it and know what to avoid. That qubit kind of disappears. It doesn’t backtrack to keep searching but quantum tunnels to where another qubit found an additional passage and starts its adventure there. The efficiency is fundamental. We don’t waste time on backtracking. Qubits are one organism. They can enter this organism and exit in another place. This is quantum tunneling.
Why, I rack my brain, do qubits entangle? This is the key to this whole phenomenon. What’s it about? Of course, physicists will show me a million equations, saying, “After all, it’s obvious! It follows from Schrödinger’s equation.” But do they themselves know what they’re saying?
I see it this way. Why do qubits, that is, physical particles, become one body at some point?
Like when two people fall in love and don’t see the rest of the world. They react only to each other. The rest as if doesn’t exist.
It’s the same with entanglement. Physical particles like lithium or calcium synchronize their de Broglie wave phases. Amplitudes are synchronized automatically because these are always the same type of particles. You can’t entangle a photon with a calcium particle because the amplitudes don’t match. It is precisely the synchronization of de Broglie waves that is the basis. Resonance of waves occurs, and they strongly amplify, so the rest of the particles are kind of unnoticed, in the distance, because the energy of resonating waves is significantly greater than the rest of randomly wavering, unbound ones. Therefore, in resonance—entanglement—particles kind of see only each other and interact essentially only with respect to each other.
In entanglement, it’s important that particles have matching de Broglie wave phases.
Cheers,
wonabru