Quantum computing is more than just a dream for scientists and engineers: it is a reality that awaits us. When we arrive at this reality that was once sci-fi fodder remains the question. Now, for the first time, researchers have successfully created an interface that allows for two machines to connect and share stored quantum information, essentially the first tangible steps towards a “quantum internet.” The feat was also achieved at a wavelength compatible with the optical fiber system we use today for telecommunications.
The breakthrough takes us closer to a world where information can be transmitted with absolute security, and complex computations can be performed at lightning speed. This is the promise of quantum technologies, which harness the bizarre properties of quantum mechanics, such as superposition and entanglement. However, realizing this potential requires the ability to transfer and store quantum information, which is typically carried by single particles of light called photons.
One of the most promising platforms for generating these photons is semiconductor quantum dots – tiny islands of material that can emit light with unique quantum properties. These quantum dots are like artificial atoms, and can be engineered to produce photons on demand, making them ideal candidates for quantum communication protocols. However, to build a functional quantum network, these photons need to be stored and processed, which is where atomic quantum memories come in. These memories use ensembles of atoms to absorb and store the quantum state of light, allowing it to be retrieved at a later time. The challenge lies in getting these two systems to talk to each other effectively.