# Experimental nonlocal steering of Bohmian trajectories

## TL;DR

This paper experimentally demonstrates nonlocal steering of Bohmian trajectories via entangled photons, showing how remote measurements influence particle paths in a way consistent with quantum mechanics and Bohmian interpretation.

## Contribution

It provides the first experimental evidence of nonlocal steering of Bohmian trajectories using entangled photons and weak measurements, illustrating a key nonlocal feature of Bohmian mechanics.

## Key findings

- Remote measurement influences Bohmian trajectories
- Experimental validation of nonlocal effects in Bohmian mechanics
- Visualization of nonlocal steering in quantum systems

## Abstract

Interpretations of quantum mechanics (QM), or proposals for underlying theories, that attempt to present a definite realist picture, such as Bohmian mechanics, require strong non-local effects. Naively, these effects would violate causality and contradict special relativity. However if the theory agrees with QM the violation cannot be observed directly. Here, we demonstrate experimentally such an effect: we steer the velocity and trajectory of a Bohmian particle using a remote measurement. We use a pair of photons and entangle the spatial transverse position of one with the polarization of the other. The first photon is sent to a double-slit-like apparatus, where its trajectory is measured using the technique of Weak Measurements. The other photon is projected to a linear polarization state. The choice of polarization state, and the result, steer the first photon in the most intuitive sense of the word. The effect is indeed shown to be dramatic, while being easy to visualize. We discuss its strength and what are the conditions for it to occur.