Now Quantum Computers Can Send Information Using a Single Particle of Light

Physicists at Princeton University have revealed a device they’ve created that will allow a single electron to transfer its quantum information to a photon. This is a revolutionary breakthrough for the team as it gets them one step closer to producing the ultimate quantum computer. The device is the result of five years worth of research and could accelerate the world of quantum computing no end.

Xiao Mi, a graduate student in Princeton’s Department of Physics, says, “We now have the ability to transmit the quantum state to a photon. This has never been done in a semiconductor device because the quantum state was lost before it could transfer its information.” The way in which the device works is by trapping an electron and photon within a device built by HRL Laboratories and owned by Boeing and General Motors. The semiconducting chip is made up of several layers of silicon and silicon-germanium, and across the top are a number of nanowires that are used to deliver energy to the chip.

Quantum computing brings with it a whole range of advantages; the main one being its capability to calculate many problems simultaneously resulting in much faster computing than anything we’re used to. Jason Petta, professor of physics at Princeton, said, “In our device, the state of the qubit is encoded in the position of the electron. The electron is trapped in a double well potential where the electron can occupy the left well, the right well, or be in a superposition state: both left and right at the same time. The information is therefore stored in the position of a single electron.”

The researchers discovered the best way for them to pass information between electrons without destroying them in the process was to use photons as they’re less sensitive to environmental factors and would be perfect for helping to form the circuits for a quantum computer. Petta goes on to say,” Just like in human interactions, to have good communication a number of things need to work out – it helps to speak the same language and so forth. We are able to bring the energy of the electronic state into resonance with the light particle so that the two can talk to each other.” The researchers will continue to do further work with the device to fine tune it to allow greater control over the transferring of information between qubits.