Routers use electromagnetic radiation to transmit information, but now, for the first time, researchers at the Autonomous University of Madrid have developed a device that redirects substances to achieve the same function.
by Autonomous University of Madrid (UAM) has also participated in the universities of Würzburg and Jena (Germany), St. Petersburg (Russia), Reykjavik (Iceland) and St. Andrews (UK). The university has managed to use optical microcavities and the so-called of Polarin.
To understand these concepts, one must remember route It is a device that uses electromagnetic radiation to transmit information. A certain amount of power is coupled to the transmission line, allowing the signal to be used in other networks or circuits.
For its part, Optical microcavity It is a structure composed of two highly reflective surfaces that surround an optical medium (such as a semiconductor). Its small size allows observation of quantum effects.
The coupling in these electromagnetic radiation structures (Light, photon) And load excitation in semiconductors (Materials, excitons) A new particle is produced: Polarin.These can be considered Child of light and matter. They share the properties of their constituents, such as the ability to interact with each other, thus providing excellent opportunities for controlling and manipulating light.
What the international team is now building is a waveguide that propagates polarons in an optical microcavity, thus realizing particle transmission between the two arms of the router (acting as a polaron coupler).
This is the first demonstration of a device that allows material redirection, similar to the normal operation performed with light today.This research has been on the cover of the magazine Advanced optical materials.
This is a pioneering work that paved the way for manipulating matter and obtaining new devices based entirely on polarons, such as lasers, logic gates, transistors, and integrated circuits. These characteristics are unimaginable even today.
The Evolution of Vactor Router
Electromagnetic radiation routers are usually used in our environment and have a very wide range of applications, such as providing sampling signals for evaluation and feedback, power combinations between antennas, providing connections for distributed cable systems such as TVs, and separating transmit signals. And received through the phone line.
But at a more complex stage, semiconductor photonic circuits are being developed, especially based on Gallium Arsenide (GaAs), In order to perform integrated photonics at the quantum level and control the state of individual photons or entangled photons, which is Quantum photonics.
This new work needs to overcome many technical and scientific challenges.One of them is to manufacture the microcavity through the following technology Epitaxial growth of molecular beams The waveguide is etched and obtained by reactive ions, thereby maintaining the high optical quality of the material.
Experimental measurements were also carried out. These measurements actually require the realization of a video with a picosecond resolution (10-12 s), and simulate the results. This allows us to understand the data and see the influence of the different parameters involved (the width and length of the guide, the injected energy and the propagation of polarons, interference phenomena, etc.).
In order to understand the difficulties to be faced, for example, it is only sufficient to consider only the spacing between the arms of the device in the coupling area of the device. 1.5 micronsThat is, one-tenth the thickness of very thin hair. During the engraving process, the quality of the semiconductor is maintained, and most importantly, the quality of the surface area is maintained, so that the propagation and coupling of polarons can be carried out.
Under the conditions of high vacuum and low vacuum, the experimental measurement also requires a high degree of complexity The temperature is close to absolute zero (10 K), a laser that provides a pulse with a duration of 2 picoseconds and a detector that allows the film to have a high time resolution, while recording the position of the polaron in space, its velocity and the propagation energy.
Rozas (E. Rozas), Jabel (J.. “The effect of high-energy landscape on the propagation of polaron condensate along the coupler”. Advanced optical materials August 2020 (2000650).
Work funded by MINECO project MAT2017-83722-R.