Enhancing Quantum Computing Using Parity

Researchers have developed a way to increase the computing rate of quantum computers by encoding the coordination of qubits.

One of the great things about quantum computers is that quantum bits or as they are known as qubits, can store data and can also work as a computer unit. But this is also a limitation, because quantum information from qubits can be copied.

To overcome this issue, the theoretical physicist Wolfgang Lechner, together with Philipp Hauke ​​and Peter Zoller, proposed a novel architecture for a quantum computer in 2015. This architecture is now known as the LHZ architecture. of the authors. The physical qubits in this architecture encode the relative coordinates between bits rather than representing individual bits. “This means that not all qubits have to interact with each other,” explains Wolfgang Lechner.

Parity computers can perform operations between two or more qubits in a single qubit. “Existing quantum computers already implement such operations on a small scale, however, as the number of qubits increases, it becomes more complex to implement these gate operations,” explained Michael Fellner. from Wolfgang Lechner’s group.
Researchers have shown that parity computers can, for example, perform quantum Fourier transforms – a basic building block of many quantum algorithms – with significantly fewer computational steps and thus faster.

The new concept offers hardware-efficient error correction. As quantum systems are very sensitive to perturbations, quantum computers must correct errors continuously. Significant resources must be devoted to protecting quantum information, which greatly increases the number of qubits required. The researchers explained that this model works with two-stage error correction, one type of error (bit flip error or wrong part) is prevented by the hardware used.

References: “Universal Parity Quantum Computing” by Michael Fellner, Anette Messinger, Kilian Ender and Wolfgang Lechner, 27 October 2022, Physical Review Letters.
DOI: 10.1103/PhysRevLett.129.180503