Atomic vacancy can act as quantum bits even at room temperature, Although boron nitride has a structure very similar to graphene, it has completely different optoelectronic properties.

Its components, the elements boron and nitrogen, are arranged in graphene as carbon atoms, similar to the hexagonal structure of bees. They are arranged in a two-dimensional layer which is only one atom thick.

The individual layers are only weakly connected to each other by the so-called Van der Waals forces and can therefore be easily separated from each other.

Physicists from Julius Maximilians University of Würzburg (JMU) in Bavaria have experimented with so-called spin centers in boron nitride crystals for the first time in collaboration with the Technical University of Sydney, Australia. Atomic vacancy can act as quantum bits even at room temperature.

In the boron nitride-coated crystal lattice, physicists have discovered a special defect in the lost boron atom that has a magnetic dipole moment, also known as spin. Apart from that, it can also absorb and emit light and is therefore called the center of color.

To investigate the magneto-optical properties of quantum transmitters in detail, JMU scientists have developed special experimental techniques that use a combination of static and high-frequency magnetic fields.

“If you change the frequency of the magnetic field back and forth, you suppress the rotational frequency at one point and photoluminescence changes dramatically,” the researchers said. Atomic vacancy can act as quantum bits even at room temperature.

However, some luck is needed because it is difficult to predict at what frequency unknown rotation conditions must be sought. Deacon and his team found these centers in 2D crystal systems that were previously only theoretically predicted.

Among other things, they can show spin polarization, ie alignment of defective magnetic moments with optical excitation even at room temperature.

This also makes the experiment interesting for technical applications: Scientists all over the world are currently working to find solid states where rotational states can be aligned, manipulated if necessary, and then read optically or electrically.

The center of rotation that we identified in boron nitride fulfills these requirements. Because it rotates and continues to absorb and emit light, it is a quantum bit that can be used for quantum sensing and information. Atomic vacancy can act as quantum bits even at room temperature.

New navigation technology can also work with this technology, which is why space agencies like DLR and NASA are doing extensive research on this topic.

For basic 2D scientists, the material is also interesting from a different perspective.

They have a very special coating structure, combined with weak layer bonds with each other, and offer the possibility of constructing different sequences for ordering from different semiconductors.

In the next step, Dyakonov and his colleagues plan to make a hetero structure from a multi-layer semiconductor with a layer of boron nitride as an intermediate layer.

They believe that it will be possible to produce artificial two-dimensional crystals based on the Lego brick principle if atomic thin layers of boron nitride, “decorated” with separate centers of rotation, can be produced and their properties integrated into heterostructural structures. to learn.