How do quantum computers work? – Easily explained


Practical tipsHardware Today, scientists are constantly working on quantum computers. Recently, IBM introduced a first quantum computer. How these work, we explain here. Qantencomputers: Qubits: Quantum computers use what are known as qubits. Normal bits on the computer can only take on two different values: 0 and 1, or “on ” and “off “. In contrast, a qubit can be in an intermediate state of zero and one for a certain period of time, the so-called coherence time. Scientists speak of a superposition in this state. By measuring the qubit then goes into one of the two clearly defined states, so you can save the measurement result in a classic bit. In technical language, the loss of superposition is called decoherence. In the laboratory, such qubits are made of ions or superconducting loops, so-called SQUIDs. When working with ions, an unexcited ion corresponds to the state 0 and an excited state to the state 1. Uninitiated is an atom with the lowest possible energy. However, if one adds energy to an atom, it is excited because external electrons reach higher energy levels. With a laser, the ions can be excited. Quantum Register – You Need to Know Several qubits are needed to solve arithmetic operations. One speaks of a so-called quantum register. The information is then distributed to all qubits of a register. Such a quantum register usually consists of 14 ions, which are stored with a few micrometers distance along an axis. Importantly, these qubits are easy to manipulate, yet immune to interference. This means that the qubits must remain in their respective states for as long as possible until the arithmetic operation has been performed. The decoherence, ie falling back into a classical state, must be postponed as long as possible. To manipulate the states, logical operators are used, which are already used in computer science. These operators are called quantum gates in quantum computers. These are decisive for the duration of the irradiation and for the wavelength of the light. The simplest operation is the negation, called NOT. The state of a qubit is simply folded or negated. In the binary system, the 0 would become a 1 and vice versa. This flipping happens very fast as well as very often in succession and follows the algorithm of the program. To determine the initial state of a quantum grid, this is irradiated with laser pulses. The length of the irradiation can be used to determine the probability with which an atom is in the excited state. After approximately ten microsecond irradiation, an initially unexcited ion is in the excited state. However, if this atom is irradiated for only half as long, it is in that intermediate state, as it is still in the ground state with a probability of 50 percent and with a probability of 50 percent in the excited state. In order to read the result after carrying out the algorithm, another laser pulse with a different wavelength is shot onto the ions. Through fluorescence, they indicate whether they are excited or not. The computer can then determine the correct values. Quantum computers work with more than just ones and zeros. (Picture: Pexels) Quantum computer: state of the art todayAt the electronics fair in Las Vegas, IBM introduced a first market-ready quantum computer this year. Compared to predecessor models, the IBM Q Systems One already expects 20 qubits, which is a benchmark for a properly functioning quantum computer , IBM says it has managed to keep 20 qubits in the prepared state for 75 microseconds. A quantum computer with 50 qubits should be able to put any classic supercomputer in your pocket. However, the IBM Q Systems One – a glass box of two and a half meters in length and width should not be offered for sale. Instead, selected users can access it via the cloud and perform calculations. From Quantum Computer to Punch Card: This is what the very first computer looked like

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