Physicists Just Broke a Quantum Record, Taking Entanglement to a Spooky New Level

From Science Alert.com (Apr. 16):

If we want quantum computers, we're going to need a complex system of quantum entangled particles - particles that are intrinsically linked so that whatever happens to one instantaneously affects another.

That's a whole lot easier said than done, of course - but a team of physicists has just breached an exciting milestone by creating a 20-bit quantum register.

Quantum bits, or qubits, are the basic building blocks of quantum computing, just like bits are the building blocks of traditional computing.

But what's challenging about them is that they rely on subatomic particles' spooky ability to exist in more than one state at the same time.

Regular bits can exist in two states - 1 or 0. Qubits would also be based on the binary system, but thanks to entanglement they can exist in a superposition of both states, rather than one or the other, as bits must do.

This would allow for a computer that is vastly faster and more powerful than the computers we currently use.

But that's only if the qubits can be combined to create a register of well-characterised, entangled qubits.

………………….

Now, Blatt and a team of physicists and theorists have built a system of 20 qubits whose quantum states can be individually controlled.

In this experiment, 20 charged calcium atoms, or ions, arranged in a line served as the qubits, and they were entangled using a series of lasers. [read more]