# The direct test of the absence of the "quantum vampire's" shadow with use of thermal light

## TL;DR

This paper experimentally tests the quantum vampire effect using thermal light, demonstrating that photon annihilation does not create a shadow but affects the beam's total intensity, challenging classical intuition.

## Contribution

It provides the first direct experimental test of the quantum vampire effect with thermal light, extending previous simplified double-mode regime studies.

## Key findings

- Photon annihilation does not produce a shadow in thermal light.
- Photon annihilation affects the total beam intensity.
- The quantum vampire effect is confirmed with thermal states.

## Abstract

Counterintuitive nature of quantum physics leads to a number of paradoxes. One of them is a "quantum vampire" effect [1] consisting in the fact, that photon annihilation in a part of a large beam doesn't change the shape of the beam profile (i. e., doesn't cast a shadow), but may change the total beam intensity. Previously this effect was demonstrated just in a simplified double-mode regime [1,2]. In the current paper the direct test of shadow absence after the photon annihilation has been performed with use of thermal state of light at the input.

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Source: https://tomesphere.com/paper/1901.03093