Quantum walks (QWs) represent paradigmatic quantum evolutions, enabling powerful applications in the context of topological physics and quantum computation. They have been implemented in diverse photonic architectures, but the realization of two-particle dynamics on a multidimensional lattice has hitherto been limited to continuous-time evolutions. To fully exploit the computational capabilities of quantum interference it is crucial to develop platforms handling multiple photons that propagate across multidimensional lattices.
Researchers have reported a discrete-time quantum walk of two correlated photons in a two-dimensional lattice, synthetically engineered by manipulating a set of optical modes carrying quantized amounts of transverse momentum. Mode-couplings have been introduced via the polarization-controlled diffractive action of thin geometric-phase optical elements.
The entire platform is compact, efficient, scalable, and represents a versatile tool to simulate quantum evolutions on complex lattices.
The team expects that it will have a strong impact on diverse fields such as quantum state engineering, topological quantum photonics, and Boson Sampling.
The paper has been published in npj Quantum Information.