In an age of super modern as when it , the invention of a tool that could help alleviate the work of man becomes a necessity that is very important . IBM (International Business Machines Corporation) and Google when it was a race to create a computer quantum that is really going to beneficial for many people. Computers Sophisticated were created for processing power in a number of large turn out has not been able to satisfy the thirst we ‘ll speed and capacity computing , which so far as it continues to evolve . But look at the history of the computer , it seems difficult to believe anything that had we achieved when these .

In the year 1947, the engineer computer with Howard Aiken said that Americans only require six units of computer digital to meet the needs of computing the state of the . While it is the experts who else has been making predictions wrong about the amount of power computing that will support the needs of the technology we are continuously evolving .

Of course , Aiken did not consider a number of big data generated by research science , the development of computers personal or emergence of the Internet, which encourages the need to be the power of computing over many and much much more .

Computer quantum is a tool arithmetic which uses a phenomenon mechanics quantum, for example superposition and linkages, to perform the operation data. In classical computing , the amount of data is calculated in bits; in a quantum computer , this is done with qubits. The basic principle of quantum computers is that the quantum properties of particles can be used to represent data and data structures , and that quantum mechanics can be used to carry out operations with this data . In this case , to develop a computer with a quantum system , a new logic that is in accordance with the principles of quantum is needed .

The idea of the computer quantum of this comes from some physicists among others Charles H. Bennett of IBM, Paul A. Benioff of Argonne National Laboratory, Illinois, David Deutsch of the University of Oxford, and Richard P. Feynman of the California Institute of Technology (Caltech).

At first Feynman put forward his idea of a quantum system that can also carry out a calculation process . Fenyman also suggested that this system could be a simulator for quantum physics experiments .

Furthermore, the scientists began to conduct research on a system of quantum such , they are also trying to find the logic that in accordance with the system of the . Until the moment it has dikemukaan two algorithms new that could be used in a system of quantum that is shor algorithm and grover algorithm .

Although quantum computers are still in development , experiments have been carried out where quantum computational operations are performed on a small number of qubits. Research both in theory and practice continue to continue the pace of the fast , and many governments national and agency funding the military supports the research of computer quantum for development both for the purposes of the people as well as issues of security nationwide as cryptanalysis.

It has been believed by very broad , that when the computer quantum in a scale large can be made , then the computers are able to resolve a number of problems more quickly than a computer ordinary . Computer quantum differ with computer DNA and computers classical -based transistors, although perhaps computer types are using the principles of quantum mechanics . A number of architectural computing such a optical computer although using superposition classic of wave electromagnetic , but without a number of sources of quantum mechanics that specific such linkages then there could potentially have the speed of computation as were owned by computer quantum .

**Principles of Quantum Computers **

Computer quantum work with a way to manipulate the principles of physics quantum . Quantum physics is the branch of physics that explains the behavior of subatomic objects . The theory of this stems from the theory of photoelectric , which states that light is composed on packets wave that acts as a particle and wave simultaneously are called photons , which is the quantity of the smallest light . Quantity smallest are referred to as quantum . In the physics of quantum there are some phenomena , such as linkages or entanglement and superposition or superposition.

Superposition is the phenomenon when a particle occupy any state or state. Each particle has two configurations , namely up ( above ) are denoted 0 and down ( bottom ) are denoted 1 as code binary computer . An in a superposition particle can occupy both together until we take measurements . Measurements ‘ force ‘ particles to occupy one of them . Once measured , the spin is fixed . Circumstances supeposisi can occur when the process of calculation takes place . Because of the ability of qubits to occupy more than one state , quantum computers can do all the calculations simultaneously . The measurement causes the qubits to stop counting and choose possible answers . Superposition provides the ability of parallelism in quantum computers. Quantum computers also apply the principle of connectedness . Relationship is simply the connection of particles by means of measuring the state or state of a particle can affect the state of other particles that are connected . The phenomenon is , although not instant , can be connected in a distance that is very far away , even most experts hypothesize linkages can ‘ reach ‘ past then. Suppose a photon is fired through the breaker rays , a tool to reflect or transmit photons polarized into directions horizontally or vertically , the photon first have spin 0 split into A and B are moved to the direction opposite . A has spin +1/2 and B has spin -1/2. When we measure A, the measurement can affect the results of B without measuring again photons B. The phenomenon of this can be applied to the qubit, the phenomenon is applied to transmit information to a computer quantum , as computer digital touch via wave radio.

**How a Quantum Computer Works **

There are several requirements for a quantum computer to work , namely :

1. It can be increased in scale , the qubit must be added continuously constantly.

2. Qubits must be set to the initial state , for example 0.

3. Interaction between qubits must be strong enough to create a quantum logic state .

4. To perform operations with a logic gate , the decoherence time must be longer than the logic gate operating time . Dekoherensi itself is the loss of quantum mechanical properties in a particle , returning it to classical conditions.

5. Must be able to read data.

6. To connect the circuits of computer , must be able to convert a qubit storage of data into qubit processing data.

7. Must be able to move qubits to place another by accurately .

**Disadvantages of Quantum Computer**

Like man- made things, quantum computers also have disadvantages, including :

- Quantum computers are able to run conventional algorithms like digital computers , but to give their full potential special algorithms are needed . Unfortunately , the algorithm for quantum computers is still very complicated to make , as are the qubits which are the basis of the information . This makes the ability of full computer quantum is still a hypothesis , abilities that developed when it was not too useful .
- Making the qubit is also not controlled by the well , scientists still had difficulties with adding the number of qubits. In addition , qubits must also be isolated from the outside world to prevent decoherence .
- The qubit must be at a temperature of about 0.02
^{0 }K or -272.8^{0 }C to operate . - The nature of the uncertainty of the quantum well become a barrier else . Computer quantum not memeberi answer concrete , but the answer is based on the possibility of the largest . Computation must be repeated several times to give a definite answer .
- Although parallelism allows the size is small for
computers quantum , size computer kauntum still fairly large rather than
computer digital. Computers Quantum has extensive 10m
^{2 }and 15,5KW to operate , the size of which is relatively small compared to the computer super, but too large for everyday . - The price of quantum computers is still very expensive, the price of one unit is around Rp 130,000,000,000, making quantum computers still very far from the domestic market . So far this kommputer quantum only owned organizations, the Organization i biggest world.