Long-range and Ultra-secure Communication Using a Nanoantenna

Nano-cavity antennas are used to improve the exceptional transmission of TM-polarized light via vertical nano-slits in a metal film. At low frequencies (including microwave), the enhanced transmission of TE-polarized waves through an array of subwavelength slits in a thin metal film is also investigated.

A nanoantenna was used by the researchers to focus light onto a single semiconductor nano box. This method will increase the utility of quantum repeater technology, which is currently being developed for advanced communication and data storage. Such technology is critical for overcoming the limitations of traditional computer information for securely sharing data over long distances.

Information storage and transfer in the form of simple ones and zeros, as used in today’s classical computer technologies, is insufficient for the development of quantum technologies. Researchers in Japan have now created a nanoantenna that will aid in the implementation of quantum information networks.

Because traditional computer information is based on simple on/off readouts, it’s relatively simple to use a technology known as a repeater to amplify and transmit data over long distances. Quantum information, on the other hand, is more complex and based on secure readouts such as electron spin.

The efficiency of converting single photons into single electrons in gallium arsenide quantum dots, which are commonly used in quantum communication research, is currently too low. As a result, we created a nanoantenna made of ultra-small concentric rings of gold to focus light onto a single quantum dot, resulting in a voltage readout from our device.

Rio Fukai

Semiconductor nano boxes, also known as quantum dots, are materials being studied by researchers in order to store and transfer quantum information. Having said that, quantum repeater technologies are constrained in a variety of ways, including the current method of converting photon-based information to electron-based information. This process is extremely inefficient, which is why the research team set out to find new ways to solve the conversion and transfer problems.

Researchers from Osaka University and collaborators have significantly improved photon-to-electron conversion via a metal nanostructure in a study recently published in Applied Physics Express, which is an important step forward in the development of advanced data sharing and processing technologies.

A nanoantenna for long-distance, ultra-secure communication

Traditional computer data is based on simple on/off readouts. It is simple to use repeater technology to amplify and retransmit this information over long distances. Quantum information is based on readouts that are relatively more complex and secure, such as photon polarization and electron spin. Researchers have proposed semiconductor nano boxes known as quantum dots as materials for storing and transmitting quantum information. However, quantum repeater technologies have some limitations, such as the inefficiency of current methods of converting photon-based information to electron-based information. The researchers at Osaka University set out to solve the problem of information conversion and transfer.

“The efficiency of converting single photons into single electrons in gallium arsenide quantum dots, which are commonly used in quantum communication research, is currently too low,” says lead author Rio Fukai. “As a result, we created a nanoantenna made of ultra-small concentric rings of gold to focus light onto a single quantum dot, resulting in a voltage readout from our device.”

When compared to not using the nanoantenna, the researchers increased photon absorption by a factor of up to 9. When a single quantum dot was illuminated, the majority of the photogenerated electrons were not trapped there, but instead accumulated in impurities or other locations in the device. Nonetheless, the excess electrons produced a minimal voltage readout that could be distinguished from that produced by the quantum dot electrons, and thus did not interfere with the device’s intended readout.

According to senior author Akira Oiwa, “theoretical simulations show that we can improve photon absorption by up to a factor of 25.” “Improving the alignment of the light source and fabricating the nanoantenna more precisely are ongoing research directions in our group.”

These findings have far-reaching implications. Researchers now have a way to advance the prospects of upcoming quantum communication and information networks by utilizing well-established nano-photonics. Quantum technology, by utilizing abstract physics properties such as entanglement and superposition, could provide unprecedented information security and data processing in the coming decades.

This new study uses well-known nanophotonics to advance quantum communication and information networks. It has the potential to lead to new types of quantum technologies with applications in information security and data processing.