Role of entanglement in quantum computation

Benoît Vermersch

Jurgen Van Gael

Dr. Johnathan Doe

Entropy plays a pivotal role in quantum computing and information theory, serving as a measure of uncertainty and information in quantum systems. This paper explores how entropy, particularly von Neumann entropy, quantifies quantum states and their evolution in quantum computing systems. We discuss the relationship between entropy and quantum entanglement, quantum error correction, and the thermodynamic properties of quantum computers. Furthermore, we examine the implications of entropy in information processing tasks, including quantum algorithms, and its role in the quantum-to-classical transition.

F. J. Duarte

Michael E. Cuffaro

Of the many and varied applications of quantum information theory, perhaps the most fascinating is the sub-field of quantum computation. In this sub-field, computational algorithms are designed which utilise the resources available in quantum systems in order to compute solutions to computational problems with, in some cases, exponentially fewer resources than any known classical algorithm. While the fact of quantum computational speedup is almost beyond doubt, the source of quantum speedup is still a matter of debate. In this paper I argue that entanglement is a necessary component for any explanation of quantum speedup and I address some purported counter-examples that some claim show that the contrary is true. In particular, I address Biham et al.'s mixed-state version of the Deutsch-Jozsa algorithm, and Knill \& Laflamme's deterministic quantum computation with one qubit (DQC1) model of quantum computation. I argue that these examples do not demonstrate that entanglement is unnecessary for the explanation of quantum speedup, but that they rather illuminate and clarify the role that entanglement does play.

Tim Forcer, Tony Hey, Douglas Alan Ross +1 more

The paper examines the roles played by superposition and entanglement in quantum computing. The analysis is illustrated by discussion of a "classical" electronic implementation of Grover's quantum search algorithm. It is shown explicitly that the absence of multi-particle entanglement leads to exponentially rising resources for implementing such quantum algorithms.