Quantum Computer

A quantum computer is a kind of obey quantum mechanics for high-speed mathematical and logical operations, storage and processing of Quantum Information Physics device. When a device processing and calculation of quantum information, quantum algorithm is running, it is a quantum computer. Quantum computer concept stems from the reversible computer studies. The study of reversible computing aims to solve the problem of energy consumption in the computer.

Quantum computer, first by Richard Feynman, starts from physical phenomena simulation to. He found that when simulating quantum phenomenon, because of the huge Hilbert space makes the data also become large, a good simulation for computing the time become quite considerable, even unrealistic astronomical figures. Richard Feynman knew, if the quantum system is constituted by the computer to simulate quantum phenomena, computation time can be greatly reduced. Quantum computer concept was born.

Quantum computer, or give extended application -- quantum information science, in the 1980's in the theoretical derivation empty talk. Until 1994 Peter shor ( Peter Shor ) quantum factoring algorithm, for now because of its passage in the bank and network such as the RSA encryption algorithm can crack and threat, quantum computing becomes a hot topic. In addition to the theory, there are many scholars focus on the use of various quantum system to realize the quantum computer. Semiconductor integrated circuit by the control of recording and operational information, quantum computers that control the atoms or small molecules state, recording and operational information.

Nineteen sixties to 70 time, people found that the energy consumption will lead to a computer chip in the heating, greatly influence the integration of the chip, thereby limiting the computer running speed. Study found that, energy consumption from computational process is not reversible operation. Then, whether the calculation process must not reversible operation can be completed? The answer is: all the classical computer can find a corresponding reversible computer, and does not influence the operation ability. Since the computer in every step of the operation can be transformed into reversible operation, so in quantum mechanics, it can use a transform to say so. Early quantum computer, quantum mechanics is actually use language to describe the classic computer, and did not use the quantum mechanical nature, such as quantum superposition and coherence. In a classical computer, basic information unit for a bit, the operand is a sequence of bits. Similarly, in a quantum computer, basic information unit is quantum bit, operational object is quantum bit sequence. The difference is, the quantum bit sequence can not only in the various orthogonal state superposition state, but also can be entangled state. These special quantum state, quantum parallel computing provides not only possible, but also will bring a lot of wonderful nature. With a classical computer, quantum computer can do any one positive transformation, in obtain output state, were measured results. Therefore, quantum calculation of the classic calculation of the great expansion, in mathematical form, classical computing can be seen as a special kind of quantum computation. Quantum computer on a stack of each component transformation, all these transformation at the same time, according to some probability amplitude superposition, given the results of the calculation, called quantum parallel computation. In addition to the parallel computation, a quantum computer to another important purpose is to simulate quantum system, this work is a classical computer can not be competent.

In 1994, Baer laboratory expert Peter shor ( Peter Shor ) demonstration of quantum computer can complete the number of operations, and faster than traditional computer. This is because unlike semiconductor quantum records only 0 and 1, can be said at the same time a variety of state. If the semiconductor computer than into a single instrument, quantum computers like the symphony orchestra, a computation can handle many different conditions, therefore, a 40 bit quantum computer, can unlock 1024 bit computers take decades to solve the problem.

Interesting quantum theory

Quantum theory of some basic argument is not" black", but its inference appears very"". We assume a" quantum" distance is the minimum distance of two points A and B. According to quantum theory, the object from the A through the A and B in any one point can be directly reached B. In other words, objects in the A suddenly disappeared, at the same time in the B point. In addition to the myth, you cannot in the macroscopic world to find an example of this. Quantum theory to people in the macroscopic world set up the " common sense" and" intuition" was all a hideous mess up.

Schrodinger the cat is on the quantum theory of an ideal experiment. The experimental contents are: the cat is very poor, it is sealed in a room, room with food poison. Poison Bottle with a hammer, a hammer by an electronic switch control, electronic switch controlled by a radioactive atom. If the nuclear decay, then alpha particles, touching electronic switch, hammer falls, smashing the poison bottle, released from inside the cyanide gas, cat die. The cruelty of the device by Austria physicist Erwin Schrodinger design, so this cat is called Schrodinger the cat. Quantum theory is that: without a lid, for observation, we will never know the cat is alive, it will always be a non die than live the superposition state, this with our everyday experience severe phase.