Top 51-qubit ?
(Fig.1) Apply laser light → change between excited and ground states
Last year, IBM claimed quantum computer with only five quantum bits (= qubit) was avalivable, and it still cannot be faster than classical computer.
The point is these IBM computers are NOT quantum computer, no matter how many qubits they adopt in vain. Because they do not use key parallel computing.
Quantum computer uses two different energy levels as bit ( ground state =0 excited state = 1 ) in atoms and superconducting artificial atoms.
Though they claim each qubit takes two energy states at the same time like a dead and alive cat, those parallel worlds cannot be observed.
Atoms are just classically alternating between two energy levels, NOT being in two states simultaneously as quantum computer claims !
(Fig.2) 50%-50% chance of detecting a qubit as 0 or 1 = classical !
Quantum computer requires each quantum bit is in two different states (= 0 and 1 ) at the same time like a dead and alive cat in parallel worlds.
But we cannot observe those fantasy parallel worlds. They just apply light to atoms alternating between two states classically instead of unseen superposition.
When we observe an atom at a time (= t2 ), it has 50% chance of being ground (= 0 ) or excited (= 1 ) states.
So quantum superposition means the probability of detecting 0 or 1 state is oscillating classically with time, NOT in both states simultaneously.
As a result, the present quantum computer can be explained by classical mechanics, and cannot be faster.
(Fig.3) ↓ IBM quantum cloud is just classical mechanics.
IBM announced their quantum computing is available to the public, though it includes only five bits, so useless.
In this quantum computer, the symbol "H" means creating superposition, which means we have 50%-50% chance of detecting qubit as 1 or 0 at this stage.
So it's just classical mechanics. At the gate "+" symbol, they change qubit2 state depending on qubit1 state using microwaves of different adjusted frequencies.
This process is also classical mechanics. They cannot do powerful parallel computing using parallel worlds at all.
So their quantum computer remains useless and slower forever, it's just a tool to deceive people and government into wasting money in fantasy dream science.
(Fig.4) When we know qubit1 is 0, it means qubit2 is 0 ← entangle !?
This IBM quantum computer claims it can create entanglement = spooky action.
But spooky action cannot be used as real tool of faster-than-light transmission, so this unseen entanglement is just a meaningless and nonsense concept.
They just adjust quantum bits using microwave, where when qubit1 is 0 (or 1), qubit2 is 0 (or 1).
The moment we know that qubit1 is 0 state, it means qubit2 is determined as 0 state (= spooky action !? )
As you see, this entanglement (= spooky action ) is just a classical meaningless phenomenon with NO physical importance. You should neglect it.
2017/7/7 updated. Feel free to link to this site.