Is a million cubit Quantum computer really possible?

[John Clark]

Denis Mandich, is the chief technology officer for the quantum computer company "Qrypt" and is quoted as saying:

“With just 300 logical qubits, you have more compute power than has ever existed and could ever exist if you turned every atom---every atom in the universe---into a supercomputer,”

We don't know how good quantum error correcting algorithms can get but estimates are that it will take between 10,000 and 100,000 of today's best physical Qubits to make one logical Qubit that has an error rate of 10^-15, which is what you need for a quantum computer to become practical. And as of today, the lowest physical Qubit error rate so far was 10^-6, one error per million operations, achieved by researchers in Sydney Australia. The better the physical Qubit is, the fewer of them you need to make a near perfect logical Qubit, and I have no doubt that over time both physical Qubits and quantum error correcting algorithms will get better, but I don't know how much time or how much better.

With all that in mind the following articles may be of some interest: 

Million qubits chip a possibility, could enable practical quantum computers (msn.com)

Anisotropic exchange interaction of two hole-spin qubits

John K Clark