Researchers including David Gosset from the Institute for Quantum Computing at the University of Waterloo; Robert König, professor for the theory of complex quantum systems at the Technical University Munich (TUM); and IBM’s Sergey Bravyi, have “conclusively demonstrated the advantage of quantum computers,” according to TUM.
The team developed a simple-structured quantum circuit, with each qubit performing a fixed number of operations. This type of circuit is referred to as having a “constant depth.” It was built to solve a certain algebraic problem, and through the researchers’ work, they’ve proven it couldn’t be solved using classical constant-depth circuits, according to TUM.
The research brought to light why classic circuits pale in comparison to the quantum option: “The quantum algorithm exploits the non-locality of quantum physics.”
“Our result shows that quantum information processing really does provide benefits—without having to rely on unproven complexity-theoretic conjectures,” says König.
According to TUM, although research suggests their merits, the advantage of quantum computers hadn’t been seen experimentally or proved before the current demonstration.
Traditional computers store data as long strings made up of binary digits (bits), which encode as either a one or a zero. A quantum computer, however, utilizes quantum bits (qubits). These qubits behave in a quantum manner, meaning they can exist in different states simultaneously in superposition, allowing a single operation to span over different states at once. Thus, the process speeds up the computing process.
This news adds to the string of quantum achievements, including ANU’s tiny camera lens that may serve as the missing link between networks and quantum computers reported in September, and the University of Bristol’s silicon chip that could bolster quantum cryptography reported in February.
In addition to providing evidence toward the advantages of quantum computer, the researchers believe its structure could help “near-term experimental realization of quantum algorithms.”
To learn more, read the article, “Quantum advantage with shallow circuits,” published in Science.