New form of universal quantum computers

Quantum computing is a field that refers to solving complex problems using the laws of quantum mechanics. As vast development is taking place we require machines that have less response time but they prove to work efficiently. Quantum computers can be useful in various fields such as Artificial Intelligence(AI), Cryptography, Molecular modeling, weather forecasting, Particle physics, etc. Quantum computers can solve such problems that a traditional computer cannot.

Keywords: Quantum machines, Universal quantum computer, qubits, LHZ architecture, parity concept, errors.

Considering the current state, the computing power of quantum machines is very low. It is very challenging for physicists to increase their power. But now they have presented a new architecture for overcoming these limitations. This universal quantum computer could be the basis of the next generation of quantum computers.

Traditionally, in a quantum computer quantum bits also known as qubits act as a computing unit as well as memory at the same time. Generally, it is not possible to copy quantum information, and cannot be stored in a memory as followed in a classical computer. Due to this drawback in quantum computers, all qubits must be able to interact with each other. Achieving this is quite challenging.

In 2015, theoretical physicists Wolfgang Lechner, Philipp Hauke, and Peter Zoller considered this situation and proposed a new architecture for a quantum computer. It is now named LHZ architecture. The name is significant as it is named after the physicists of this research.

Wolfgang Lechner of the Department of Theoretical Physics at the University of Innsbruck, Austria said, "This architecture was originally designed for optimization problems. In the process, we reduced the architecture to a minimum in order to solve these optimization problems as efficiently as possible. The physical qubits in this architecture do not represent individual bits but encode the relative coordination between the bits. This means that not all qubits have to interact with each other anymore".

Physicists have now proven that the parity concept is also suitable for universal quantum computers. Parity computers can basically perform operations between two or more qubits by using a single qubit. They have shown that parity computers can perform quantum Fourier transformations. It is basically a building block of many quantum algorithms. Thus, this requires fewer computation steps along with less response time. 

Michael Fellner from Wolfgang Lechner's team explains, " Existing quantum computers already implement such operations very well on a small scale. However, as the number of qubits increases, it becomes more and more complex to implement these gate operations. However, as the number of qubits increases, it becomes more and more complex to implement these gate operations".

Generally, quantum systems are more prone to disturbances. Quantum computers must correct these errors continuously. Anette Messinger and Kilian Ender, members of the Innsbruck research team said, "Our model operates with a two-stage error correction, one type of error (bit flip error or phase error) is prevented by the hardware used. The other type of error can be detected and corrected via the software". 

Thus, this will create a way for the next generation of universal quantum computers to be realized with manageable effort.