Quantum computer systems are ‘buggy’. Their very nature requires immense cycles of validation. Rice University computer scientists believe their algorithm, Projected Factored Gradient Decent (ProjFGD), reduces the number of measurements many-fold. “It takes advantage of compressed sensing, a method that minimizes the amount of incoming data while ensuring accurate results.” Using a form of quantum state tomography, the team’s ProjFGD images the systems qubits. In a quantum system, the qubits change state as they are processed according to their programming. It is the state at the end of the program that is your result. You need to verify the qubits are behaving correctly at every opportunity to ensure the result is as accurate as possible. Examining the full state at the completion of the program is the goal as the examination should reveal hardware and software errors. With the number of qubits in quantum computing systems growing, each additional qubit provides exponential opportunity for error in results. Studying the errors is key to future efficiency in quantum computer programming and, in the end, quality, reliable results.
