# Relative multiplexing for minimizing switching in linear-optical quantum computing

## TL;DR

This paper introduces relative multiplexing (RMUX), an optimization technique that significantly reduces active switching in linear-optical quantum computing, leading to lower hardware complexity, energy use, and improved performance in entangled state generation.

## Contribution

The paper presents RMUX, a novel optimization method that reduces switching requirements in LOQC, enabling more efficient and scalable quantum photonic architectures.

## Key findings

- Achieves an order of magnitude increase in Bell state generation rate.
- Allows a 2.4x increase in loss tolerance for 3D cluster state percolation.
- Reduces hardware complexity and energy consumption in LOQC implementations.

## Abstract

Many existing schemes for linear-optical quantum computing (LOQC) depend on multiplexing (MUX), which uses dynamic routing to enable near-deterministic gates and sources to be constructed using heralded, probabilistic primitives. MUXing accounts for the overwhelming majority of active switching demands in current LOQC architectures. In this manuscript, we introduce relative multiplexing (RMUX), a general-purpose optimization which can dramatically reduce the active switching requirements for MUX in LOQC, and thereby reduce hardware complexity and energy consumption, as well as relaxing demands on performance for various photonic components. We discuss the application of RMUX to the generation of entangled states from probabilistic single-photon sources, and argue that an order of magnitude improvement in the rate of generation of Bell states can be achieved. In addition, we apply RMUX to the proposal for percolation of a 3D cluster state in [PRL 115, 020502 (2015)], and we find that RMUX allows a 2.4x increase in loss tolerance for this architecture.