Quantum interface bound electrons and photons

Optical fiber plays an important role in transferring large amounts of information over long distances, but until now there was no device that could transfer quantum information from chips on photons.

Scientists have developed a device that mediates the interaction between photons and individual electrons. This is the first experimental prototype quantum switch chip, which can be the basis for the development of quantum computer networks. The results were published in the journal Nature Nanotechnology.

Researchers have created a photonic crystal that is able to capture photons within a microscopic cavity. These cavities are quantum dots, which contains a simple electron. Due to the small size of the cavities in the photons that fall into the crystal, begin to affect the quantum effects by the electron. To understand how the interaction between electrons and light, the scientists used a method of polarization interferometry.

A quantum dot acting as an optical resonator, who missed only photons with a certain polarization. Electron in the quantum dot can be in several quantum states due to the spin direction. Scientists are able to change the spin of a magnetic field. If the spin was in the same state, the polarization of a photon has not changed, however, when a different state right polarization of the photon is changed to the left. Similarly, the right-handed photons can change the spin of the quantum dot.

In this system, the quantum dot is the quantum gates - a basic logic element that works with qubits, quantum information storage units. With the help of photons, which may act as carriers of information, a qubit can change the quantum state of the other qubit. Such a device, scientists believe, could be the basis to create quantum analog fiber-optic networks.

Quantum networks allow you to transfer quantum information between different storage of quantum information devices. To create them, the fiber optic cable can be used, in which information carriers are photons.