Recently, researchers at TU Wien have succeeded in coupling the specific defects in two diamonds with one another. This coupled diamonds could help for the development of highly sensitive sensors and switches for quantum computers.

In fact, quantum states are very fragile and decay very quickly so Coupling between quantum systems is a rare phenomenon. However, it is one of the important pre-requisite for many quantum technological applications. That is why researchers at TU Wien carried out their study to find quantum systems that can be used for technical applications.

During the study of the quantum properties of diamonds, they have succeeded in coupling only the specific defects in two diamonds. Even though they discovered some potential candidates, up until now there has been no system that fulfills all of the requirements simultaneously.

Regarding this, Johannes Majer said, Diamonds with very specific defects are one potential candidate for making quantum computers a reality. Johannes Majer is head of the hybrid quantum research group. However, the detailed outcome related to coupled diamond experiment published in the journal Physical Review Letters.

While describing the defected coupled diamond Majer added that a lattice structure of a pure diamond contained only the carbon atom. However, some diamonds have impurities at some lattice points. Those points are occupied by nitrogen atoms instead of the carbon atoms. Besides, other anomalies showed the absence of atom at some points, which referred as the vacancy.

Moreover, both types of defective diamonds are scarcely coupled and formed a quantum system with a very long-lasting state. In fact, this combined nitrogen-vacancy system is ideal for quantum experiments. Though, the interaction between nitrogen-vacancy diamonds of the coupled diamonds system is very weak. It has reached of around 10 nanometers.

Furthermore, researchers used Albeit's superconducting quantum chip that produces microwave radiation. With the help of this, researchers are studying and manipulating or coupling these two types of defective diamonds. According to Majer, billions of nitrogen-vacancy diamonds are coupled and produced the quantum system during the process.

In addition, they extend their research by coupling two different diamonds, previous they used the same type of diamonds. In this experiment, they will place diamonds at both ends of the quantum chip. The Interaction between two diamonds is mediated by the microwave resonator in the chip. Here Resonator acts as the similar role of a data bus in the normal computer, says Johannes Majer.

The coupling between the diamonds can be switched on and off selectively. According to lead author Thomas Astner, two diamonds are rotated against each other at a certain angle. In this project, they used the magnetic field for the decisive role, if both diamonds are aligned at the same angle within the magnetic field, then they can be coupled using quantum physics. Otherwise, they need further investigate without coupling.