Most physicists and computer manufacturers think quantum computers will replace the silicon chips currently in use.
Dr. Michiu Kaku, renowned theoretical physicist, author, and television personality, when referring to the potential of atomic scale computing writes, "The most ambitious proposal is to use quantum computers, which actually compute on individual atoms themselves. Some claim that quantum computers are the ultimate computer, since the atom is the smallest unit that one can calculate on. (Michiu Kaku, "Physics of the Future: How Science Will Shape Human Destiny and Our Daily Lives by the Year 2100.")
Wikipedia defines a Quantum Computer as, "a device for computation that makes direct use of quantum mechanical phenomena, such as superposition and entanglement, to perform operations on data. Quantum computers are different from traditional computers based on transistors. The basic principle behind quantum computation is that quantum properties can be used to represent data and perform operations on these data."
In simpler language, quantum computing makes use of Atomic Scale Integration, or, making computations on atoms themselves. And, rather than referring to bits of information - the smallest discrete piece of manipulatable data - quantum information is measured in qubits.
Quantum computing - early to present
Most physicists and computer manufacturers think quantum computers will replace the silicon chips currently in use. A similar evolution in processing technology occurred in the mid to late 1950's when transistors replaced the technology used at the time, the vacuum tube.
Although evolutionary technology is needed to fully utilize the computing power of quantum mechanics, the development of this technology is already hotly contested.
The race began in 1998 when Los Alamos and MIT research partners were able to spread a discrete unit of information across many different nuclear oscillations, in a solution of acid molecules. The suspension allowed different states to be analyzed as quantum information. The race was on: to build a smaller and more functional quantum based platform to measure additional qubits.
It took a couple of years before the next step. This was accomplished by scientists at Los Alamos National Laboratory when they developed a quantum computer inside a drop of liquid! The manipulation of particles in the water molecule was quite interesting and produced a 7 qubit quantum phase, blowing away all previous quantum data manipulation achievements.
Fast forward six years, and Canadian company D-Wave was able to produce a 16 qubit quantum computer able to compute several complex patterns and identify matching systems. This work ushered in the present phase of technological advancements in the world of quantum computing and is often cited as the standard for future investigations.
On the heels of this accomplishment, Graphene was discovered in 2004. This substance has been hailed as a new kind of wonder substance - though it's essentially a form of carbon, similar to pencil lead. Graphene is the king of small - it's just one atom thick - and it's highly conductive. Earlier in 2011 IBM built the first graphene circuit and now it says it can build graphene chips using production lines usually used for silicon, which bodes well for mass production.
Quantum computing - The promise
Technology changes and moves faster than most of us realize. The processing power that many companies have harnessed is faster than most ever thought possible, but as fast as our current computer technology is, it remains quite slow. The world's fastest super computer, Japan's K computer has approximately the processing power of one human brain. There are some things the K computer can do as fast as an average human, some things such as pattern recognition, more slowly. By comparison, and although we are still very far from mastering this application of quantum mechanics; researchers have estimated that a quantum computer no bigger than a laptop has the potential to perform the equivalent of all human thought since the dawn of our species in a tiny fraction of a second!
As you can see, once quantum computing technology is mastered, the amount of calculations possible will be larger than life.
Elementary quantum computers are in use in laboratories worldwide today. Although a practical workplace option is still somewhat off in the future, today's basic machines require only sounder fundamental system architectural design to emerge as commonplace future computing technology.
Despite the discoveries that have been made in the manipulation of atomic particles with micro sized computing systems, the reality of quantum computing is still quite limited. There are still huge challenges to overcome. As Dr. Kaku relates, "When atoms are coherent and vibrating in phase with one another, the tiniest disturbances from the outside world can ruin this delicate balance and make the atoms decohere, so they no longer vibrate in unison. Even the passing of a cosmic ray or the rumble of a truck outside the lab can destroy this balance". Unfortunately, when atoms decohere it is impossible to make any calculations. Additionally, the very nature of uncertainty on the quantum level gives rise to computational challenges. It turns out that all calculations done on a quantum computer are uncertain, so you have to repeat the experiment many times. So 2 + 2 = 4, but only sometimes. If you repeat the calculation of 2 + 2 a number of times, the final answer averages out to 4. So even arithmetic becomes fuzzy on a quantum computer.
Dr. Kaku concludes with, "The decoherence problem and uncertainty issues are the most difficult barriers to creating quantum computers. Anyone who can solve these challenges will not only win a Nobel Prize but also become the richest person on earth."
The future awaits!