Written by Steve Koppes
Researchers at the U.S. Department of Energy’s Fermi National Accelerator Laboratory and their collaborators have identified a new type of nanostructural imperfection that impacts superconducting qubits, the building blocks of quantum computers.
Fermilab’s Alexander Romanenko and his colleagues describe the origin of the performance-limiting materials, known as nanohydrides, in a paper posted Aug. 23, 2021, on the arXiv.org e-Print archive.
Identifying the new precipitant and understanding what causes it provides an important step toward finding a solution and improving the qubits’ performance. One of the main opportunities to improve superconducting qubits is through extended coherence times—how long they can store quantum information.
Research conducted in the Superconducting Quantum Materials and Systems Center will lead to increased coherence in superconducting transmon qubits and development of a beyond-state-of-the-art quantum computer. Future applications of quantum computers may include modeling climate change and extreme weather events, developing pharmaceuticals, improving traffic patterns and creating financial models.
Currently, superconducting transmon qubits can maintain coherence from between a few microseconds up to hundreds of microseconds. Nanohydride formation has now been identified as one of the factors that contribute to short coherence times.
“Now we can start to understand how these defects occur,” said Matt Reagor, director of engineering at Rigetti Computing and a co-author of the paper. “We can start to engineer them out of our systems.”