Encoding patterns for quantum algorithms

• Published in: IET quantum communication Vol. 2; no. 4; pp. 141 - 152
• Main Authors: Weigold, Manuela, Barzen, Johanna, Leymann, Frank, Salm, Marie
• Format: Journal Article
• Language: English
• Published: Shenzhen John Wiley & Sons, Inc 01.12.2021; Wiley
• Subjects: Algorithms; Architecture; Coding; computational complexity; Computers; Quantum computers; Quantum computing; quantum computing techniques; quantum entanglement; Quantum mechanics; Quantum physics; Qubits (quantum computing); Random access memory; Software
• ISSN: 2632-8925; 2632-8925
• DOI: 10.1049/qtc2.12032

As quantum computers are based on the laws of quantum mechanics, they are capable of solving certain problems faster than their classical counterparts. However, quantum algorithms with a theoretical speed‐up often assume that data can be loaded efficiently. In general, the runtime complexity of the loading routine depends on (i) the data encoding that defines how the data is represented by the state of the quantum computer and (ii) the data itself. In some cases, loading the data requires at least exponential time that destroys a potential speed‐up. And especially for the first generation of devices that are currently available, the resources (qubits and operations) needed to encode the data are limited. In this work, we, therefore, present six patterns that describe how data is handled by quantum computers.