Quantum Computing: Diode-like Breakthrough Surmounts Roadblock
PORTLAND, Ore.—Quantum computing gained two new key components recently from the Niels Bohr Institute, at the University of Copenhagen—one is a diode-like component that allows single photons to be emitted and flow in only one direction depending upon whether their spin is with either “up” or “down.”
The second is a kind of photon delay line. Using these new photonic components adds two more critical components to the quantum computer toolbox, bringing it closer to fruition.The Niels Bohr team is wasting no time getting patents in place. “Our research focus is on the development of photonic hardware for quantum technology and [we] may have a number of technological applications, both short term and longer term. For that reason we have secured patents of the photonic circuits and are considering the commercial potential of our prototype devices,” professor Peter Lodahl told EE Times.”Up until now, all quantum encoded photons would travel down waveguides in either direction regardless of their spin encoding, but Lodahl, along with fellow professor Søren Stobbe and their post-doctoral assistants—Sahand Mahmoodian and Immo Söllner—designed a quantum dot single-photon emitter that sends up-spin single photons in one direction down a waveguide and down-spin single photons in the opposite direction, creating a quantum computer component that sorts and separates quantum-bits qubits depending on their encoding.