# Erasing the orbital angular momentum information of a photon

## TL;DR

This paper demonstrates that the orbital angular momentum (OAM) information of a photon can be erased using quantum entanglement and polarization projection, revealing wave-particle duality in a new abstract path framework.

## Contribution

It introduces a novel quantum eraser scheme replacing physical slits with OAM states and shows the OAM information can be erased via polarization measurements.

## Key findings

- OAM content can be erased using polarization projection.
- Fringe visibility depends on whether OAM information is erased.
- The scheme extends to delayed measurement scenarios.

## Abstract

Quantum erasers with paths in the form of physical slits have been studied extensively and proven instrumental in probing wave-particle duality in quantum mechanics. Here we replace physical paths (slits) with abstract paths of orbital angular momentum (OAM). Using spin-orbit hybrid entanglement of photons we show that the OAM content of a photon can be erased with a complimentary polarization projection of one of the entangled pair. The result is the (dis)appearance of azimuthal fringes based on whether the \which-OAM" information was erased. We extend this concept to a delayed measurement scheme and show that the OAM information and fringe visibility are complimentary.