Digital devices are getting smaller and more powerful each day, and that trend hasn’t slowed because their components are constantly shrinking.
Moore’s law, an observation of this phenomenon, shows that the number of transistors per square inch on integrated circuits (chips) doubles every year. But the physical properties of particles mean that this can’t go on forever. The good news is there’s a breakthrough with more potential than all conventional computing combined: quantum computing.
Before we continue, let’s explain what a transistor is. The transistor is the fundamental building block of modern electronic devices. In a microchip, it is used as an on-off switch. The current can either pass through (“1” or “on”) or be prevented from doing so (“0” or “off”). Connecting those “blocks” and reading their states is how modern computers “think” and do everything from displaying this article to calculating complex equations, and the resulting data is stored as a series of 0s and 1s called “the bit.”
The more of these semiconductor devices you can fit on the integrated circuit, the more complex calculations it can handle, and the more powerful the chip. So transistors need to become smaller and smaller. But when the silicon transistor reaches a certain size (currently 7 nanometers), a phenomenon known as quantum tunneling occurs. The electron that travels to the semiconductor is no longer being obstructed by it. Instead, because of the device’s small size, the electron can actually, yes, tunnel through it. When that happens, a transistor in the circuit cannot switch off the current and has a permanent state of “1,” rendering any and all calculations impossible.
The end of regular chips
Breakthroughs are being made, seemingly allowing for even smaller transistors (1 nanometer) by using different materials (carbon nanotubes and molybdenum disulfide instead of silicon), but there’s still a lot of work and research to be done before those can be viable products. And even then, it would only stall Moore’s law. The Semiconductor Industry Association, the lobby group that includes industry giants Intel Corp. INTC, -0.45% Advanced Micro Devices Inc. AMD, +0.24%International Business Machines Corp. IBM, -0.71% and Western Digital Inc.WDC, +0.87% published a report that concludes that by 2021 there will be no economic gain from shrinking transistors any further.
The strategy for industry leaders is simple. Instead of making chips smaller, let’s make more of them, and have them specialized for certain tasks. That way, the computing power of an individual device will still have room to increase, even though the improvement will not result from the smaller size of its components. To that end, Nvidia Corp. NVDA, +0.02% is selling artificial-intelligence (AI) chips, and Intel’s recent acquisition of Mobileye points to the production of computer-vision chips.
What’s so special about quantum computers? In conventional electronic devices, memory consists of bits with just one value, either 0 or 1. In quantum computing, however, a quantum bit (or qubit) has both values in varying degrees at the same time. This is called quantum superposition. These ubiquitous states of each qubit are then used in complex calculations, which read like regular bits: 0 and 1.
Since qubits can store more information than regular bits, this also means quantum computers are capable of processing much greater quantities of information than standard devices. Having four bits allows for 16 possibilities, but only one at a time. Four qubits in quantum superposition, however, let you calculate all 16 states at once. This means that four qubits equal 65,500 regular bits. In the same vein, 300 qubits are equal to the estimated number of all particles in the universe. Each qubit added to the quantum computing system increases its power exponentially.
Now that you know why qubits are so special, you’ll be happy to hear that just a few weeks ago at the 2017 International Conference on Quantum Technologies, Mikhail Lukin, an experimental physicist and a professor at Harvard University, announced that he and his team had successfully built a 51-qubit quantum computer. For the time being, this makes them the most successful among those engaged in the quantum race. The runner-up was Google (the main subsidiary of Alphabet Inc.GOOG, -0.03% ) with a 49-qubit computer.
New types of computers
So what does this mean for you? Will you be able to play better games, watch high-definition movies and do other things you’ve been doing on your computer, but faster? As it stands now, this isn’t likely. Quantum computers excel not in providing results quickly, but in doing so with the least amount of steps, and only in certain situations, where particular types of algorithms can be used. This means they might be slower, currently, than your regular PC at simple tasks.
However, if you’re running complex simulations or cryptography, handling gigantic databases or performing multi-level calculations, expect quantum computers to offer you speed and power beyond anything that was previously possible, with the circumvention of limitations (such as quantum tunneling) as a bonus. This is why many now believe in “quantum supremacy,” or that in the near future, quantum computers will replace their classical counterparts altogether, by optimizing their algorithms until they can outmatch those used by conventional computers.
Do you think a quantum computer will ever replace your laptop? Please let me know in the comment section below.