How to operate a quantum computer? - Simply explained

In the case of a quantum computer, called Qubits are used.

• Normal Bits on the computer can only accept two different values: 0 and 1, respectively "on" and "off". A Qubit can, however, time, however, for a certain period of time, the so-called Coherence, in an in-between state of Zero and One are.
• Scientists speak in this state of a Superposition. By a measurement of the Qubit is then in one of the two clearly defined States, so you can save the measurement result in a classical Bit. In technical language is called the loss of the Superposition Decoherence.
• In the laboratory, such Qubits from ions or superconducting loops, so-called SQUIDs, are produced.
• If you are working with ion, corresponds to a non-excited Ion to the state 0 and an excited state 1. As a non-excited Atom with the lowest possible energy is called. Add to this, a nuclear energy, it is excited, because outer electrons are in higher energy levels. With a Laser, the ions can be excited.

To Solve calculations for several Qubits are needed. One speaks of a so-called quantum register. The Information is then distributed to all the Qubits of a register.

• Such a quantum register usually consists of 14 ions, which are stored with a few microns distance along an axis. It is important to manipulate these Qubits in a simple, but also immune against interference.
• This means that the Qubits must remain in the respective States, to the arithmetic operation has been carried out. The Decoherence, i.e., the falling Back into a classical state, must be long delayed.
• For the Manipulation of the States of the logical operators are used, which are also already applied in computer science. These operators are known in quantum computers , quantum gates. These are crucial for the duration of the irradiation, and the wavelength of the light.
• The simplest Operation is the Negation, NOT called. The state of the Qubits is in the folded position, simple or negated. In the binary System, the 0 would become a 1 and Vice versa. This flipping happens very quickly and very often in a row, and follows the algorithm of the program.
• The initial state of a quantum lattice set, it is irradiated with laser pulses. By the length of the irradiation, the probability can be determined, with the help of an Atom in the excited state.
• After about ten micro-seconds irradiation of an initially non-excited Ion is in the excited state. If this Atom is, however, irradiated only half as long, it is located in that in-between state, since it is located with a probability of 50 percent even in the ground state and with a probability of 50 per cent in the excited state.
• In order to Perform the algorithm, the result is read out, shot another laser pulse with different wavelength on the ion. By fluorescence of this type to detect whether you are excited or not. The Computer can determine the correct values.

At the consumer electronics show in Las Vegas, IBM has this year, a first-to-Market quantum computers are presented.

• Compared to previous models, attributed to the IBM Q system, One with 20 Qubits, what is a scale for a properly functioning quantum computer is. IBM has managed to keep 20 Qubits for 75 micro-seconds in the prepared state.
• A quantum computer with 50 Qubits should be able to plug in any classical Supercomputer in the pocket.
• The IBM Q-system One - a glass box with two and a half meters in length and width should, however, be offered for sale. Instead, the selected users can access via the Cloud, and run calculations.

In the next practical tip we show you how binary and hexadecimal numbers convert can.