A Quantum Development: Massive Hyperfine Interaction in a Lu(II) Qubit

Published September 12, 2022

Pulsed electron spin-echo spectra recorded at 94GHz and 5K, for the three compounds shown.

Electron spin coherence was enhanced through engineering of so-called clock transitions in molecular magnets, an advance in quantum computing strategies. The use of clock transitions to enhance quantum coherence is employed in trapped-ion quantum computers, an approach that may also be viable in magnetic molecules to yield next-generation quantum technologies.

What did scientists discover?

High-power pulsed electron spin-echo measurements at high magnetic fields demonstrate that it is possible to exert synthetic control over the hyperfine coupling between electron and nuclear spins in molecular lanthanide compounds. In turn, this allows chemists to enhance electron spin coherence via engineering of so-called clock transitions.

Why is this important?

The strategy of employing clock transitions to enhance quantum coherence is employed in trapped-ion quantum computers. This study shows that the same approach is viable in magnetic molecules, which show promise for next-generation quantum technologies because chemical self-assembly of magnetic molecules may eventually prove to be more scalable than trapped-ion architectures.

Who did the research?

K. Kundu¹, J. R. K. White², S. A. Moehring², J. M. Yu², J. W. Ziller², F. Furche², W. J. Evans², S. Hill¹

¹National MagLab and Florida State University; ²University of California, Irvine

Why did they need the MagLab?

Studies of spin coherence require advanced spectrometers that operate in pulsed mode. The strong electron-nuclear hyperfine coupling deduced from this study gives rise to huge spectral splitting patterns that are not resolvable using commercial low-field instruments; hence the need for the HiPER spectrometer at the MagLab (Figure). Several other features of this instrument proved essential for this investigation, including (i) its uniquely high-power (1kW) that enables coherent spin manipulations on nanosecond timescales, and (ii) a rapid sample loading capability that facilitates rapid transfer of the air-sensitive samples that were synthesized under cryogenic conditions and shipped to the MagLab under liquid nitrogen.

Details for scientists

View or download the expert-level Science Highlight, Massive Hyperfine Interaction in a Lu(II) Qubit
Read the full-length publication, 9.2-GHz clock transition in a Lu(II) molecular spin qubit arising from a 3,467-MHz hyperfine interaction, in Nature Chemistry. Data Set

Funding

This research was funded by the following grants: G. S. Boebinger (NSF DMR-1644779); F. Furche (NSF CHE-2102568); W. J. Evans (NSF CHE-1855328); S. Hill (DOE DE-SC0020260)

For more information, contact Stephen Hill.