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New, better way to build circuits for world's first useful quantum computers

Monday, June 27, 2016

The era of quantum computers is one step closer as a result of research published in the current issue of the journal Science. The research team has devised and demonstrated a new way to pack a lot more quantum computing power into a much smaller space and with much greater control than ever before. The research advance, using a 3-dimensional array of atoms in quantum states called quantum bits -- or qubits -- was made by David S. Weiss, professor of physics at Penn State University, and three students on his lab team. He said, "Our result is one of the many important developments that still are needed on the way to achieving quantum computers that will be useful for doing computations that are impossible to do today, with applications in cryptography for electronic data security and other computing-intensive fields."

The new technique uses both laser light and microwaves to precisely control the switching of selected individual qubits from one quantum state to another without altering the states of the other atoms in the cubic array. The new technique demonstrates the potential use of atoms as the building blocks of circuits in future quantum computers.

The scientists invented an innovative way to arrange and precisely control the qubits, which are necessary for doing calculations in a quantum computer. "Our paper demonstrates that this novel approach is a precise, accurate, and efficient way to control large ensembles of qubits for quantum computing," Weiss said.

The paper in Science describes the new technique, which Weiss's team plans to continue developing further. The achievement also is expected to be useful to scientists pursuing other approaches to building a quantum computer, including those based on other atoms, on ions, or on atom-like systems in 1 or 2 dimensions. "If this technique is adopted in those other geometries, they would also get this robustness," Weiss said.