I have been hearing, and I have been following quantum computer (ideas and prototypes) for many years and I saw progress but the end of the line is nowhere nearer, at least this is my impression.
Intel has showcased its 49Qubit quantum chip, Tangle Lake, at CES 2018 (which is an amazing feat but it is not a quantum computer that can be take the so called quantum supremacy (the point when QC will make today’s computers history).
IBM is fighting back with their 50 Qubits announced at the end of last year and showcased their prototype in February 2018.
Google followed suit in March with Bristlecone sporting 72 Qubits.
Impressive, isn’t it? After years of struggling to in the single digit area in just a few months research has been able to get close to 3 digits. Well, actually 72 Qubits is not as close to 100 Qubits as it might seem at first glance.
Additionally, to really get a quantum supremacy in computing you would need something over 1,000 Qubits. The problem (and the nice thing) about QC is that the number of Qubits sustain a parallel processing of all possible combination, that is 2**Qubit (2 at the power of Qubit). This is an exponential number and getting 1,000 Qubit power would mean the capability to address 2**1000 (or 10 followed by 300 zero, and that is a pretty big number, far far bigger than the estimated number of elementary particles in the known Universe), BUT it would also mean to have the capability of managing the coherence of all those states (and correcting errors that inevitably would pop up).
This with the current, and foreseen technology, is just out of the question.
This is basically the point being made in the editorial comment on Slashdot and I am fully in synch with that.
Now, don’t take me wrong. This is an exciting area of research, but it is creating a lot of hype and practical results are no-where in sight. Should we drop it since, at least for the foreseeable future the quantum supremacy will remain at the end of the rainbow? No, I don’t think so. This is an exploration journey and I am sure that on the way a lot will be discovered that can result in useful application. It is not about the destination but it is about the journey.
There are, however, concrete (still challenges) practical application of quantum ICT as shown in the roadmap for quantum communications. We already have a few applications, and products, for quantum cryptography, an area that will become ever more important in the coming decade as more and more data value will be tied to data flowing through communications networks. Their volume, as shown in the roadmap, is expected to grow into the Exabyte range by 2040. In that timeframe QC is still allocated in the yellow research band.