Joint Wire Cutting with Non-Maximally Entangled States

TL;DR

This paper explores how non-maximally entangled states can optimize joint wire cutting in distributed quantum computing, reducing the sampling overhead and improving efficiency over previous methods using maximally entangled states.

Contribution

It introduces a method to minimize sampling overhead for joint wire cuts using NME states, including analysis of composite states and an optimal cutting technique.

Findings

Minimal sampling overhead for joint wire cuts determined

Composite NME states analyzed for overhead reduction

Optimal wire cutting technique with pure NME states developed

Abstract

Distributed quantum computing leverages the collective power of multiple quantum devices to perform computations exceeding the capabilities of individual quantum devices. A currently studied technique to enable this distributed approach is wire cutting, which decomposes a quantum circuit into smaller subcircuits by cutting their connecting wires. These subcircuits can then be executed on distributed devices, and their results are classically combined to reconstruct the original computation's result. However, wire cutting requires additional circuit executions to preserve result accuracy, with their number growing exponentially with each cut. Thus, minimizing this sampling overhead is crucial for reducing the total execution time. Employing shared non-maximally entangled (NME) states between distributed devices reduces this overhead for single wire cuts, moving closer to ideal teleportation with maximally entangled states. Extending this approach to jointly cutting multiple wires using NME states remained unexplored. Our paper addresses this gap by investigating the use of NME states for joint wire cuts, aiming to reduce the sampling overhead further. Our three main contributions include (i) determining the minimal sampling overhead for this scenario, (ii) analyzing the overhead when using composite NME states constructed from smaller NME states, and (iii) introducing a wire cutting technique that achieves the optimal sampling overhead with pure NME states, paving the way towards wire cutting with arbitrary NME states.