Quantum Computing and Quantum Revolution
Living in this technology oriented world, we can observe how quickly the devices we use are improving. They are getting faster, smaller and more convenient at an alarming rate. An average computer today is about 1000 times faster compared to a computer 15 years ago. We just accept that this how technology works and rarely think about some key questions. HOW are engineers able to improve the performance of the computers consistently at such a rate? Is it possible to keep improving the speed of our computers at this rate? If not, WHAT is the future of computing? To answer these questions, I will need to first briefly explain the building block of a processor: Transistor.Â
Transistors (combination of Transmitters and Resistors) are semiconductors capable of amplifying or rectifying an electric signal. They act as tiny switches that either enable or disable the flow of electricity by physically connecting or disconnecting two wires. This action is triggered by an electric impulse received by transistors. Transistors, being semiconductors, can conduct and enable the flow of electricity or insulate and disable the flow of electricity, thus giving us the basic structure of binary: 1 (conduct) or 0 (insulate). Transistors are usually made of silicon as silicon, after doping, is an excellent semiconductor at room temperature. Therefore, transistors form the basic building blocks for a processor, which means more the transistors, potentially faster the processor.Â
Mooreâs Law says that the number of transistors in an Integrated Circuit (CPU, microprocessor) doubles roughly every 18 months. This law of exponential growth of the number of transistors turned out to be quite accurate, as the world moved from a computer with 2000 transistors in 1973 to about 350 million in 2006. However after 2010, the world couldnât keep up with this growth rate. Today, we have computers with about 1.5 billion transistors which is around 5 times less that the Mooreâs law estimate. This is because, in order to increase the number of transistors we need to decrease the size of a transistor. In 1970s we started of with transistors that were visible to a human eye. Today, we have transistors with a width of about 30 nano-meters, which is about the size of a few hundred atoms. So, the final question comes down to just how small can we make a transistor?
There is obviously a limit to how physically small transistors can get. For starters, they cannot be smaller than the size of an atom. But, if we do more research and follow basic laws of physics, I donât see the size of transistors going much below 10 nano meters. Which potentially gives us room for ONLY TWICE the number of transistors that we have now. Even if we go down to this size, there are a lot of challenges we will have to face. First, having this many transistors processing terabytes of data in a small space will lead to significant increase in temperature (by 100s of degrees) and eventually the transistors will reach their melting point. Moreover, if a transistors depends only on a few atoms that makes it less reliable and not affordable. Furthermore, a chip consisting of such transistors will have a huge energy demand that easily exceeds our capacity given the resources we have. And finally, the phenomenon of Quantum Tunneling and Heisenberg Uncertainty Principle: When weâre dealing with distances in tens of nano meters, we cannot ignore the fact that electrons will behave in an unpredictable manner which would further lead to corruption of data and computational errors.Â
So what really is the solution? Thereâs work going on in Optical Computing which uses photons instead of electrons as they are a million times faster, literally. Thereâs more progress made in Thermal computing, which isn't as fast as Optical Computing, but is easier to implement. But, I can see these two technologies reaching their limit within the next 50 years. What we need is a technology which has capacity to improve exponentially as the time passes by; A technology that will never reach its limit; A technology that is connected to the universe and functions according to the minutely detailed laws of the universe itself. We need Quantum Computing. Richard Feynman said that Universe via quantum mechanics itself is an ultimate parallel computer. I agree. We need a Quantum computer that could work according to simulation of physical systems in a quantum mechanical device, in other words Quantum Simulation. There are various other quantum algorithms and quantum hardware ideas that are in progress currently. I will talk more about them in my next posts. But, whatâs disappointing is that Feynman came up with this idea in 1982 and we still havenât made huge progress in this direction. I really think Quantum computing is the future of computing and technology. Itâs a time for a Quantum Revolution!














