When quantum computing becomes a mainstay in everyday devices it will undoubtedly be among the most profound advances the technology industry has ever seen. However, unlike previous breakthroughs, progress has taken decades and research has been exceptionally costly for companies involved in the efforts. After all, designing a computer that utilizes quantum bits (qubits) and associated quantum mechanics instead of the standard binary bits used in modern computers, is a painstaking and unforgiving process. Rather than simply scaling components down and improving efficiency, it requires scientists to rethink how computers do or can work from the ground up. That means completely new considerations for every component from storage to processing and everything in between. In fact, challenges surrounding the build-out of a true quantum computer may be best surmised in the form of a popular quote by the late theoretical physicist Richard Feynman. According to Feynman, "If you think you understand quantum mechanics, you don't understand quantum mechanics."
To begin to understand both the implications of the technology and why it is taking so long for them to become mainstream - or even practical - it is important to comprehend at least the basics of quantum computing. That includes a basic understanding of what it is, what it could ultimately mean for the technology industries, and the basic history of the concept up until this point. The whole idea started with the abovementioned physicist way back in 1982 when Feynman first theorized quantum computing. But it wasn't until more than a decade later that the technology's implications began to be understood. That started with a realization that quantum computers would effectively nullify modern encryption methods - which is a fact that remains true. From there, the first true quantum computer didn't appear until 2016 thanks to efforts made by IBM. So, it took around 34 years to go from conceptualization to implementation. In the world of technology, that's already an extremely slow pace but things have moved forward. The company moved from that first 5-qubit machine to a claimed 50-qubit processor as of November 2017.
So how does quantum computing work and what does it mean for technology? In the simplest terms, a quantum computer processes qubits of information instead of standard bits, as mentioned above. That is, however, an oversimplification. What makes them so intriguing are the mechanics linked to quantum processes. A qubit is unlike a normal computer bit in that it is not necessarily binary. Instead of being represented as off or on, as a 0 or 1, a quantum bit can effectively hold either or both positions. What's more, because of entanglement, multiple qubits can act as a single qubit, which would allow multiple computations to take place at the same time, without necessarily impacting the speed of computation. If implemented in a stable fashion, those two things would theoretically result in computer systems that are millions of times faster and more powerful than the most powerful computers on Earth at the time of this writing. That doesn't just mean that computer games and smartphones would be better for users, either. As some in the industry describe it, quantum computing could make solutions to the most difficult mathematically-solvable questions in science attainable. The technology could also be the final key in creating the first true A.I., as well as almost immediately making current cryptology methods pointless - while also likely being the source of brand new security methods and advances in A.I. related fields of the industry such as self-driving cars.
To get to the point where quantum computers render every other computing system far beyond obsolete, companies developing them still need to overcome some significant challenges. For starters, the most challenging problems quantum machines could potentially solve may require up to a million qubits. Even scaling at multiples of 10 per year, as IBM was able to do in order to move from 5 qubits to 50, that puts those machines at least 5 years away. Worse, that figure depends on companies continuing to make those kinds of leaps and bounds forward, which is by no means a guarantee. In fact, some in the industry believe the solution is still 10 years or more away. Google and Microsoft believe progress will be much faster. In fact, Google had previously announced a goal to reach that point - known as quantum supremacy, in the industry - by the end of 2017. The search giant has plans to offer up quantum computer access to researchers. Obviously, the company has not yet hit that point, although it did manage to use quantum computing to solve at least one problem that current computers would have great difficulty in addressing.
Microsoft has also been making bold claims about its own efforts in the field. If true, its claims would be truly groundbreaking in that they would effectively have solved the largest problem facing the technology. While qubits are notoriously unstable and difficult to work with - making any upward scaling a massive step forward - the company claims that its own qubits will basically be completely stable. Current iterations of the technology have required a large number of qubits just to offset the fact that those bits are unstable and only held in a quantum state for a very small amount of time. Moreover, interacting with qubits fundamentally alters them which means that quantum computers as they now exist exert as much or more effort in correcting errors as they do actual computing. Microsoft is looking to solve that by creating a qubit that fragments itself in order to effectively store information in multiple locations in a single qubit. The company has not said that it has discovered a way to make that happen, but company spokespersons have suggested that Microsoft's quantum computer would only need one qubit for every 1,000 or more used by the competition.
Bearing all of that in mind, it is easy to see why quantum computers are not on Best Buy shelves or working their way into smartphones. Looking past those challenges, according to some industry leaders, quantum computers also need to operate at much lower temperatures than previous computers have required. Even the task of maintaining a stable and usable temperature in a modern gaming rig can be a substantial challenge. Meanwhile, that's also a challenge that the companies involving themselves in quantum computers have not publicly addressed. So it may be a good idea to take claims from those companies with a grain of salt, for the time being.