Phys.org November 29, 2021
It is challenging to construct large numbers of gates for photons and connect them in a reliable fashion to perform complex calculations. Researchers at Stanford University have proposed a scalable architecture for a photonic quantum computer using readily available components – a fiber optic cable, a beam splitter, a pair of optical switches and an optical cavity, and the size of the machine doesn’t increase with the size of the quantum program you want to run. The design consists of two main sections – a storage ring and a scattering unit. The storage ring is a fiber optic loop holding multiple photons that travel around the ring; each photon represents a qubit. The photon’s direction of travel around the storage ring determines the value of the qubit. Because photons can simultaneously exist in two states at once, an individual photon can flow in both directions at once, which represents a value that is a combination of 0 and 1 at the same time. The photon can be manipulated by directing it from the storage ring into scattering unit to a cavity containing a single atom. They become entangled. When photon returns to the storage ring and a laser alters its state and its paired photon. By measuring the state of the atom, you can teleport operations onto the photons. Only one controllable atomic qubit is needed as it can be used as a proxy to indirectly manipulate all the other photonic qubits… read more. Open Access TECHNICAL ARTICLEÂ
Photonic quantum computer architecture described in this work…Credit: Optica Vol. 8, Issue 12, pp. 1515-1523 (2021)Â