If you pay attention to the tech world you have undoubtedly heard of quantum computers. It is believed that it will be the next great leap forward in modern computers and it is certainly exciting to think about. But what exactly is quantum computing? We will try to answer that for you today.
What Is Quantum Computing?
Quantum computing was first theorized in 1981 by American physicist Paul Benioff showing that a computer could operate under the laws of quantum mechanics (which we will not attempt to try to explain as we are not scientists nor do we play one on TV). Technology of the time made this only a theory and today it is still only a hypothetical model but it is getting closer to reality.
Computers have been based off of the simple design of the Turing machine since the 1930s where a device has a theoretical tape of unlimited length divided into squares. These squares can either have a 1 or a 0 or be left blank. A read-write device is used to read what is in the square or to write something into that square. This information is used to provide instructions to the machine to operate various programs and is measured in bits. These machines are capable of performing one calculation at a time today.
1 Or 0
Quantum machines are not limited to 1 or 0 but instead can be both and information is encoded as quantum bits or qubits. These qubits use ions, photons and electrons to work together as both computer memory and as a processor. Because it can exist as these multiple states at the same time it is possible to be millions of times more powerful than existing computers.
An easy analogy was put forth by an article in Scientific America. A coin can be either heads or tails and with normal operation it is easy to figure that out, just put one out on the desk in front of you. But spin the coin on the surface and the coin can be both heads or tails at the same time. A qubit can represent both 1 and 0 the same way that coin can be both heads or tails.
Control devices are used to control the particles. Ion traps are used to trap ions and optical traps are used to trap and control particles. Quantum dots are semiconductors used to contain and manipulate electrons, which are contained in impurities in the semiconductor. Superconducting circuits allow the electrons to flow with little resistance and at a very low temperature, Qubits have to be kept cold to keep them stable, about -273 degrees Celsius or just above absolute zero.
Thanks to this parallelism a quantum computer has the potential to work on millions of computations at once. Compare that to a modern computer which can only work on one computation at a time and you can see the benefits. Eventually these will eventually replace the silicone chips that we have come to depend on.
What’s Holding Quantum Computing Back
A big reason why quantum computing has not yet reached possibility is physics. Since subatomic particles are being used it is possible to bump those particles and change their value. In order for quantum computing to be possible the integrity of the system has to be preserved to avoid this, which can be caused by noise, temperature changes or electrical fluctuations.
To do this scientists are turning to a process called entanglement where an outside force is applied to atoms and it allows those atoms to take on the properties of the first. This will cause one atom to spin in one direction and the other to spin in the opposite direction which would allow scientists to know the value of a qubit without actually looking at it. The qubit must also be kept very cold and right now to keep them at the required -273 degrees Celsius (-459 degrees Fahrenheit) requires a 55 gallon drum with a special isotope of helium. Certainly not a cheap proposition for the average person.
In order for quantum computers to be commercially viable it is estimated that it will need more than one million qubits. In order to develop an understanding of what software or hardware can be developed a system of several thousand qubits will be necessary. Size will also be a problem as a one million qubit system will be very large.
Quantum Computing In The Real World
Most of what is related to quantum computing is theoretical as the technology necessary to make this possible is simply not available. That is of course not to say that scientists are not working on it. The first breakthrough came in 1998 when researchers at MIT and Los Alamos were able to create a single qubit and were able to study entanglement. Two years later at Los Alamos scientists were able to create 7 qubits in a single drop of liquid and solved some mathematical problems using it. The following year scientists from IBM and Stanford University developed a 7 qubit quantum computer to determine factors of 15.
Some of the technology that was theoretical when originally postulated has become reality. In 2005 researchers at the University of Michigan built an ion trap and in 2009 researchers at Yale built a 2 qubit superconducting chip.
In 2011 a Canadian company called D-Wave Systems claimed to have built a 128 qubit processor and sold one to Lockheed Martin. Scientists did not believe that they had actually built a quantum computer and are still divided on that. D-Wave is one of the leaders having developed a quantum system in 2007 capable of solving a Sudoku puzzle. The first quantum teleportation of one macroscopic object to another was reported in 2012 by scientists in China. In 2015 Australian researchers built a quantum logic gate out of silicon. A few weeks later D-Wave demonstrated the first quantum operational quantum computer with NASA.
The Quantum Computer Race
The first nation that can develop a working quantum computer will have a great advantage over others and the company that can develop the first true working model will also have a great advantage. With potentially millions of times more processing power it is easy to see why it would be of great interest to companies, militaries and governments around the world. It has the power to help take us to the stars or to help solve the many problems in this world.
How soon could a true quantum computer be a reality. Australian researchers in 2013 said that a working model was only 5-10 years away so we’re getting close but it seems that their prediction is just a little off. In reality it may take another decade before a working model with a few thousand qubits is available and much longer before a working model is available for public purchase.
Last week Google made the claim that quantum computers had achieved supremacy over classical computers when a quantum processor was able to perform a task in 200 seconds that Google claimed would take a modern supercomputer 10,000 years to do. While IBM disputes the 10,000 year claim, saying it was more like 2 ½ days this is a major advancement. It was done with 53 qubits, which does make everyone wonder just how powerful these machines could be.