Quantum computers operate on the principles of quantum mechanics, which simply stated is the study of how matter and light behave at an atomic and subatomic level. They promise to outperform today’s supercomputers or tomorrow’s supercomputers for that matter. What we are talking about is ( I deeply apologize for the pun, but I can’t help myself) a quantum leap in computing.
Although quantum computing is still in the experimental stage, companies are attempting to develop quantum computers to develop new drugs, find cures for illnesses, and perhaps design the next great engineering marvel.
Quantum computers rely on their ability to produce and manipulate quantum bits, called qubits.
Today’s computers process bits, which are electrical or optical pulses that represent 1s or 0s. Everything from the movie you stream to Facebook posts are composed of these binary digits.
However, quantum computers process qubits, which are usually such subatomic particles as photons or electrons.
It is a massive scientific challenge to produce and manipulate these particles. Tech companies such as Google and others, utilize superconductivity to cool circuits to approximately -452 degrees, which is just above absolute zero. Another method to control qubits is to “trap” individual atoms within an electromagnetic field on a silicon chip, under ultra-high vacuum conditions to achieve what is called a controlled quantum state.
Qubits behave in a bizarre manner that allows a group of them to connect together to provide far more processing power than a computer using the same number of traditional bits. One such behavior is the result of a property in physics called superposition, and another is called entanglement.
Superposition
Qubits can represent a number of possible permutations of 1 and 0 simultaneously. This phenomenon that allows simultaneous multiple states is known as superposition. To put qubits into superposition, researchers place qubits in superposition using microwave energy or lasers. a quantum computer using qubits in superposition can calculate vast numbers of potential outcomes at the same time. The end result of a calculation is known only by measuring the qubits, at which point their quantum state “collapses” to either 1 or 0.
Entanglement
Scientists can procure pairs of qubits that are “entangled,” which simply means each of the two exist in one quantum state. When you change one qubit’s state,it will instantly change the state of the other one in a manner that can be predicted, this occurs even if the qubits are separated by inordinately long distances.
Not even great scientists like Einstein could explain what he called “spooky” behavior. Doubling the number of bits in a traditional computer doubles its process power, but doubling qubits increases computing power at a nearly exponential rate.
Quantum computers arrange entangled qubits in a daisy chain configuration to speed up calculations. Quantum computers utilize specially designed “quantum” algorithms to achieve what seems like magic by today’s standards. Now, as Paul Harvey would say, here is the rest of the story—unfortunately quantum computers are prone to errors because of decoherence.
Decoherence
When qubits interact with their environment in such a way that their quantum behavior deteriorates, and eventually disappears the result is decoherence. The quantum state of qubits is exceedingly delicate. The smallest change in temperature or the tiniest vibration can result in the qubits leaving superposition before their task is complete. These disturbances are called noise.
But despite keeping qubits at temperatures approaching absolute zero and in nearly perfect vacuums, these disturbances can cause errors when crunching data.
Intuitive algorithms can often compensate, as does adding more qubits. It will, in all likelihood however, require thousands, if not tens of thousands of “standard “qubits to generate one reliable qubit, which is called a “logical” qubit.
Currently, scientists have been unable to produce more than 128 standard qubits. This means quantum computers have a long way to go before dominating traditional digital computers.
Quantum computers can calculate vast numbers of potential solutions at mind-boggling speeds. It has been said by a number of researchers that quantum computing could rapidly accelerate the development of artificial intelligence.
What I have presented is only a rudimentary explanation of quantum computing, for more information, go to computer.howstuffworks.com/quantum-computer1.htm
