Zero-index metamaterials offer new insights into the foundations of quantum mechanics

It is always good to look at things from different perspectives.

Since the beginning of quantum physics, how light moves and interacts with matter around it has mostly been described and understood through the lens of its energy. In 1900, Max Planck used energy to explain how light is emitted by heated objects, a seminal study in the foundation of quantum mechanics. Albert Einstein used energy when he introduced the concept of photon.

Light has another quality called momentum. Light behaves in interesting ways when momentum is taken away.

An international team of physicists led by a research associate at the Harvard John A. Paulson School of Engineering and Applied Sciences and a professor at the Balkanski Professor of Physics and Applied Physics are re-examining the foundations.

Nature Light: Science and Applications contains the research.

Any object with mass and speed can be transferred from one object to another. When a bullet is fired, the gun recoils because it transfers the bullet's momentum to the gun. An atom recoils when it emits light because of the acquired momentum of the photon. Einstein described atomic recoil when he was writing the quantum theory of radiation.

A new class of metamaterials is raising questions about the fundamental phenomena after a century. When light travels through these metamaterials, it doesn't travel like a wave in phases of crests and troughs. A constant phase is created by stretching the wave out to infinite. Atomic recoil is one of the typical processes of quantum mechanics.

Why? It all goes back to normal. When the wave momentum of light is zero, odd things happen.

In three-dimensional near-zero index materials, fundamental radiative processes are not allowed.

If breaking one of Einstein's rules wasn't enough, the researchers also broke Young's double-slit experiment. This experiment is used in classrooms across the globe to demonstrate the particle-wave duality in quantum physics, showing that light can display characteristics of both waves and particles.

A bright spot in the center of the screen can be formed by two waves of light that interfere to form a bright spot in the center of the screen with a pattern of light and dark fringes on either side.

When we modeled and numerically computed Young's double-slit experiment, it turned out that the fringes vanished when the Refractive index was lowered.

The work probes the limits of wave-corpuscle duality and examines fundamental laws of quantum mechanics.

Some fundamental processes are not affected by near-zero Refractive index materials. The Heisenberg inequality is a famous quantum phenomenon. The principle states that you can't know the position and speed of a particle with perfect accuracy if you don't know about the other. You have absolutely no idea where the particle is in the material, because you know with 100% certainty that the momentum of the particle is zero.

The material would make a really poor microscope, but it would allow objects to be hidden.

New theoretical results shed new light on near-zero Refractive index, which can be useful for lasing.

Light sources that emit a single photon at a time, the lossless propagation of light through a waveguide, and other applications could be shed light on by the research.

The team wants to revisit other quantum experiments in these materials. Einstein stressed the importance of momentum even though he did not predict near-zero Refractive index materials. In his 1916 paper on fundamental radiative processes, Einstein insisted that from a theoretical point of view, energy and momentum should be considered on a completely equal footing.

Physicists aspire to follow in the footsteps of giants like Einstein and push their ideas further.

More information: Michaël Lobet et al, Momentum considerations inside near-zero index materials, Light: Science & Applications (2022). DOI: 10.1038/s41377-022-00790-z Journal information: Light: Science & Applications Citation: Zero-index metamaterials offer new insights into the foundations of quantum mechanics (2022, April 27) retrieved 27 April 2022 from https://phys.org/news/2022-04-zero-index-metamaterials-insights-foundations-quantum.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.