Researchers discover a new type of quantum entanglement

Technology – A pioneering study by the Israel Institute of Technology reveals a newly discovered form of quantum entanglement, the total angular momentum of the confined photons in nanoscale structures – only one thousandth of the width of a human hair. This discovery may play a key role in the future miniaturization of quantum communication and computing components

The study was published in nature and led by a PhD. Amit Kam and Shai Tsesses, a Ph.D., currently a postdoctoral fellow at MIT, worked with distinguished professors Moti Segev and Meir Orenstein. Other contributors include Dr. Yigal Ilin, Dr. Kobi Cohen, Dr. Lior Fridman, Stav Lotan (Andrew and Erna Viterbi College), Dr. Yaakov Lumer, Dr. Anatoly (Tolik) Patsyk (Tolik) Patsyk and Liat Nemirovsky-Lelevy (Department of Physics).

Quantum physics sometimes leads to unconventional predictions. When Albert Einstein and his colleagues, Boris Podolsky and Nathan Rosen (who later established the School of Physics in technical terms) discovered a scenario in which it is known that the state of one particle immediately affects the state of another, no matter how great the distance between them is, that’s what happens. Their historic 1935 paper was nicknamed EPR, with three authors (Einstein – Podolsky – Rosen).

The idea of ​​knowing that a particle’s state affects another particle that is a great distance away from it, without physical interactions and information transfer seems ridiculous to Einstein, who called it “a weird effect in the distance.” But another technical researcher, the pioneering work of Asher Peres of the School of Physics, shows that the property can be used to transmit information in a hidden way – quantum transmission, which is the basis for quantum communication. The discovery was conducted by Professor Perez with his colleagues Charles Bennett and Gilles Brassard.

The phenomenon, which later received the scientific name Quantum Entanglement, and its measurements and implications, including the possibilities of quantum computing and quantum communication, awarded the 2022 Nobel Prize in Physics to professor. Alain Factex and Anton Zeilinger previously received honorary doctorates from Technion, as well as their colleague Professor John Clauser.

To date, quantum entanglement of various particles and their various properties has been demonstrated. For photons, the direction of travel of light particles, frequency (color), or direction of electric field points may exist. For more difficult properties, such as angular momentum, it may also exist. This characteristic is divided into spin, which is related to the photon rotation and orbit of the electric field, which is related to the rotational motion of the photons in space. This is intuitively similar to the Earth, which rotates on its axis and rotates the sun in a circular path.

It is easy for us to think of these two rotational properties as separate numbers, and in fact, the photons bound to the beam are much wider than the wavelength. However, when we try to put photons into structures smaller than the wavelength of the photon (which is an effort in the field of nanophotonics), we find it impossible to separate different rotational properties, and the photons are characterized by a single number, total angular momentum.

So why do we even want to put photons into such a small structure? There are two main reasons for doing this. One is obvious – it will help us miniaturize the device using light, thereby squeezing more operations into a small area, similar to miniaturization of electronic circuits. Another reason is even more important: This miniaturization increases the interaction between photons and materials that propagate (or are close to) the photons, allowing us to create phenomena and uses, in their “normal” dimensions, photons are not available in their “normal”.

In a study published in nature, technical researchers found that it is possible to entangle photons in nanoscale systems that are one thousandth of the size of hair, but entanglement is not performed by conventional properties of photons, such as rotation or trajectory, but by total angular momentum.

Technological researchers have revealed the process from the stages of introducing photons into nanoscale systems until they exit the measurement system, and have found that this transition enriches the space where photons can reside in a series of measurements. In a series of measurements, the researchers identified these states as uniform quantums at the nanoscale and confirmed the same quantum and confirmed the range of quantums.

This is the first time in more than 20 years that new quantum entanglements have been discovered, which could lead to the development of new tools for designing photon-based quantum communication and computing components, as well as their important miniaturization.

This study was obtained by the Innovation Bureau (Magnet Program), the Israel Science Foundation (ISF), the Technology Technology Center, the Technology Center and the Nanoelectronics Center (MNFU) and the Helen Diller Quantum Center.