Quantum Entanglement of 16 Million Atoms

Quantum communication, a reality to the future communication system has taken a bold step forward in achieving this reality. The theory of Quantum Mechanics that predicts a vast number of atoms can be entangled and intertwined by a very strong relationship has been shown experimentally by the scientists at the University of Geneva (UNIGE), Switzerland. They demonstrated the successful entanglement of 16 million atoms in a one-centimeter crystal.

 The idea behind developing Quantum Communication system is of data protection especially in the encryption industry, which can now guarantee the customer of safe communication by immediately detecting the interception by a third party. To send and receive these kinds of signals, there is the requirement of quantum repeaters which basically operates on the idea of entanglement. These repeaters are basically made of crystal blocks supercooled to 270 degrees below zero and enriched by rare-earth-ion.

This is a partial view of the source producing the single photons that were stored in the quantum memory to produce entanglement between many atoms inside the memory. (Credit: UNIGE)

Splitting a photon, produces two entangled photons having identical properties and behaviors which is relatively an easy process. Florian Fröwis, a researcher in the applied physics group in UNIGE’s science faculty, says, “But it’s impossible to directly observe the process of entanglement between several million atoms since the mass of data you need to collect and analyze is so huge.” In order to avoid the present complexity, Fröwis and his colleagues chose a more indirect route, considering about the measurements that could be undertaken to curb the problem. In the experiment, they investigated the characteristics of re-emitted light from the crystal, which also includes the statistical analysis of its properties and the probabilities. The investigation was carried out following two major approaches, firstly, the light is re-emitted in a single direction rather than radiating uniformly from the crystal; and secondly, it is made up of a single photon.

Scheme of the experiments. (Credit: Matthias Fink et al. | Nature Communications)

Particle entanglement is a prerequisite for the quantum revolution that is on the horizon, which will also affect the volumes of data circulating on future networks, together with the power and operating mode of quantum computers. Everything, in fact, depends on the relationship between two particles at the quantum level—a relationship that is much stronger than the simple correlations proposed by the laws of traditional physics.

The result of the UNIGE experiment has been published in Nature Communications.


Source: Futurism, Science Daily, Phys.org, Nature

The author is a research fellow at the Indian Institute of Science Education and Research (IISER), Pune, Maharashtra. Presently, he is working in the field of quantum information processing at Quantum Optics and Atomic Physics laboratory. He is very enthusiastic in writing scientific articles and interested in developing scientific equipment.