Breakthrough in Quantum Computing Achieved by HRL Laboratories
HRL Laboratories, LLC, has made a breakthrough in the field of quantum computing. The team has published the first demonstration of universal control of encoded spin qubits in Nature. This novel silicon-based qubit device architecture was fabricated in HRL's Malibu cleanroom and involves trapping single electrons in quantum dots. Energy-degenerate qubit states of three individual electrons can be manipulated through contact interactions with their neighboring electrons, which partially exchange the spin states.
The demonstration involved applying thousands of precisely calibrated voltage pulses in strict relation to one another over the course of a few millionths of a second. The team worked hard to develop efficient, automated routines for determining what applied voltage led to what degree of partial swap. This was very much a team effort, with the enabling work of talented control software, theory, device growth and fabrication teams being crucial.
The success of this experiment means that the qubits can be used for any kind of quantum computational algorithm implementation. The silicon exchange-only qubit is believed to be the best-balanced technology, but there are still challenges in improving error, scale, speed, uniformity, crosstalk, and other aspects.
Once realized at scale, quantum computers would differ from traditional supercomputers in that they use quantum entanglement to perform certain calculations in a very short time that would take traditional computers years or decades. Possible applications range from materials development to drug discovery to the development of processes for mitigating climate change.
0. “First demonstration of universal control of encoded spin qubits” Phys.org, 7 Mar. 2023, https://phys.org/news/2023-03-universal-encoded-qubits.html
1. “Quantum Computing Breakthrough: Silicon Encoded Spin Qubits Achieve Universality” SciTechDaily, 6 Mar. 2023, https://scitechdaily.com/quantum-computing-breakthrough-silicon-encoded-spin-qubits-achieve-universality/