What is a Quantum Computer?
In quantum computation we use quantum physics to compute. The use of physics in computation raises some deep philosophical problems concerning the relation of math to physics. It concerns the definition of the term ‘computer’ as a physical object. We usually take a classic physical object to compute with. Here we take a quantum physical object to do the computation.
A quantum computer is any device that exploits quantum mechanical phenomena to run algorithms. Because quantum computers have fundamentally different computational properties than conventional computers, data held in quantum computers is referred to as qubits rather than bits. In conventional computers data is represented by microscopic grooves on a hard disk. In a quantum computer, data is represented by the quantum properties of a given molecule or set of molecules. Instead of performing computations by retrieving data from a hard disk and processing it using an integrated circuit filled with logic gates, quantum computers process data by bombarding the information-containing molecule with short pulses of radiation. Each bombardment cycle represents an algorithmic operation on the data contained within the molecule. When the algorithm terminates, the quantum state of the molecule is measured, a process which itself biases the end result. This is due to the fundamentally uncertain nat
There are two ways quantum mechanics both use the idea of a qubit. The qubit is a quantum particle that is in a state of flux it can store either a one or a zero or(this is the crazy part) or anything in between. Think the old Schrodinger’s cat analogy. The bit is in a constant flux of all the different possible answers at the same time until it’s observed crazy stuff. This ability allows you to store data on the qubit as well as do calculations with them those are the two main aspects. The qubit can also be entangled with another one which Einstein described as spooky action at a distance. You see it’s not limited by the theory of relativity which Einstein didn’t believe at the time was possible. You can have a quantum bit on the other side of the universe if it’s entangled, your bit you will see the results of that bit at the same time. This along with the superposition of the qubit(where it can be 1,0 and everything in between) makes it an impressive improvement over our current com
All computers so far, no matter how powerful, operate along the same guiding principles. The Information Age has seen an amazing development in the application of those principles. This development has been so astounding as to seem almost limitless in its extent. It does of course have bounds though. Those bounds are determined by the laws of physics upon which computation rests. Thus far computation has rested on the laws of physics as they stood in the 19th Century; what physicists refer to as ‘classical mechanics’. Quantum Computers operate on an entirely new paradigm for information processing. The laws of physics which bind them are those of ‘Quantum Mechanics’. In its simplest form a classical computer operates by inputting a set of instructions (algorithm) into an operational state of the computer. The computer then changes its state along the guidelines of the algorithm and produces its output. Often this output will then be fed back into the computer to produce further output.
