Multi-Photon, Multi-Dimensional Hyper-Entanglement using Higher-Order Radix qudits with Applications to Quantum Computing, QKD and Quantum Teleportation

Google recently announced that they had achieved quantum supremacy with 53 qubits (base-2 binaries or radix-2), corresponding to a computational state-space of dimension 253 (about 1016). Google claimed to perform computations that took 200 seconds on their quantum processor that would have taken 10,000 years to accomplish on a classical supercomputer [1]. However, achieving superposition and entanglement of 53 qubits is not an easy task given the environmental noise that decoheres the qubits. In this paper, we claim that one can potentially achieve a similar computational dimension with fewer qudits (not qubits) where each qudit is of a higher radix (greater than 2) using a photonics system (i.e. 16 qudits with radix-10). This paper is a collaborative development between industry and NxGen Partners to explore such an approach. There is a Raytheon technology that uses a Free-Space Optical (FSO) Fabry-Perot Etalon that eliminates the need for adaptive optics [2, 3]. The NxGen technology uses multiple Orbital Angular Momentum (OAM) modes as a new degree of freedom for quantum computing and a multi-dimensional QKD [4-7]. We also claim that the convergence of both broadband, secure communications, quantum computing and quantum teleportation is only possible in a photonics realization. Therefore, the use of photonic qudits allows the extension of security and capacity of the quantum teleportation beyond what was achieved by Chinese Micius quantum satellite [8]. Both the defense and commercial computing industries need such quantum computing systems. A new measure is introduced with computational state-space dimension, high-fidelity operations, high connectivity, large calibrated gate sets, and circuit rewriting toolchains. This new measure which we call quantum capacity is a practical way to measure and compare progress toward improved system structure of a universal quantum computer.