Really good breakdown on what a Quantum computer is!

[BIAD]

...For whatever reason, I can't get my head around how Quantum computing works!
One probably needs to be a physicist to understand it but maybe that's the point.  You don't need to know
how it works to program or use it.  

Scary stuff though.  I can't imagine what things will be like in 40 years.

Ignoring the fact this is completely out of my league, I will merely copy-and-paste what someone
else says is the crux of a 'Quantum computer'.

'...The secret to a quantum computer’s power lies in its ability to generate and manipulate quantum bits, or qubits.

What is a qubit?
Today's computers use bits—a stream of electrical or optical pulses representing 1s or 0s. Everything from your
tweets and e-mails to your iTunes songs and YouTube videos are essentially long strings of these binary digits.

Quantum computers, on the other hand, use qubits, which are typically subatomic particles such as electrons or
photons. Generating and managing qubits is a scientific and engineering challenge. Some companies, such as
IBM, Google, and Rigetti Computing, use superconducting circuits cooled to temperatures colder than deep space.

Others, like IonQ, trap individual atoms in electromagnetic fields on a silicon chip in ultra-high-vacuum chambers.
In both cases, the goal is to isolate the qubits in a controlled quantum state.

Qubits have some quirky quantum properties that mean a connected group of them can provide way more processing
power than the same number of binary bits. One of those properties is known as superposition and another is called
entanglement.

What is superposition?
Qubits can represent numerous possible combinations of 1 and 0 at the same time. This ability to simultaneously
be in multiple states is called superposition. To put qubits into superposition, researchers manipulate them using
precision lasers or microwave beams.

Thanks to this counterintuitive phenomenon, a quantum computer with several qubits in superposition can crunch
through a vast number of potential outcomes simultaneously. The final result of a calculation emerges only once
the qubits are measured, which immediately causes their quantum state to “collapse” to either 1 or 0.

What is entanglement?
Researchers can generate pairs of qubits that are “entangled,” which means the two members of a pair exist in a
single quantum state. Changing the state of one of the qubits will instantaneously change the state of the other
one in a predictable way. This happens even if they are separated by very long distances.

Nobody really knows quite how or why entanglement works. It even baffled Einstein, who famously described it
as “spooky action at a distance.” But it’s key to the power of quantum computers. In a conventional computer,
doubling the number of bits doubles its processing power. But thanks to entanglement, adding extra qubits to
a quantum machine produces an exponential increase in its number-crunching ability.

Quantum computers harness entangled qubits in a kind of quantum daisy chain to work their magic. The machines’
ability to speed up calculations using specially designed quantum algorithms is why there’s so much buzz about
their potential...'

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