# Experimental generalized quantum suppression law in Sylvester interferometers

## TL;DR

This paper introduces a new suppression law for Sylvester interferometers, experimentally verifies it, and demonstrates its potential for certifying quantum interference in boson sampling, outperforming Fourier interferometers.

## Contribution

It proposes and experimentally validates a generalized suppression law for Sylvester interferometers, enhancing quantum interference certification methods.

## Key findings

- Suppression is stronger in Sylvester than Fourier interferometers.
- Experimental verification with 4- and 8-mode devices confirms the law.
- Potential applications in boson sampling certification.

## Abstract

Photonic interference is a key quantum resource for optical quantum computation, and in particular for so-called boson sampling machines. In interferometers with certain symmetries, genuine multiphoton quantum interference effectively suppresses certain sets of events, as in the original Hong-Ou-Mandel effect. Recently, it was shown that some classical and semi-classical models could be ruled out by identifying such suppressions in Fourier interferometers. Here we propose a suppression law suitable for random-input experiments in multimode Sylvester interferometers, and verify it experimentally using 4- and 8-mode integrated interferometers. The observed suppression is stronger than what is observed in Fourier interferometers of the same size, and could be relevant to certification of boson sampling machines and other experiments relying on bosonic interference.