Long-lived heteronuclear spin-singlet states in liquids at a zero magnetic field

M Emondts; M P Ledbetter; S Pustelny; T Theis; B Patton; J W Blanchard; M C Butler; D Budker; A Pines

doi:10.1103/PhysRevLett.112.077601

Long-lived heteronuclear spin-singlet states in liquids at a zero magnetic field

Phys Rev Lett. 2014 Feb 21;112(7):077601. doi: 10.1103/PhysRevLett.112.077601. Epub 2014 Feb 18.

Authors

M Emondts¹, M P Ledbetter², S Pustelny³, T Theis⁴, B Patton⁵, J W Blanchard⁴, M C Butler⁴, D Budker⁶, A Pines⁴

Affiliations

¹ Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Worringer Weg 1, 52074 Aachen, Germany.
² Department of Physics, University of California, Berkeley, California 94720, USA and AOSense, 767 North Mary Avenue, Sunnyvale, California 94085, USA.
³ Department of Physics, University of California, Berkeley, California 94720, USA and Center for Magneto-Optical Research, Institute of Physics, Jagiellonian University, Reymonta 4, PL-30-059 Kraków, Poland.
⁴ Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA and Department of Chemistry, University of California, Berkeley, California 94720, USA.
⁵ Department of Physics, University of California, Berkeley, California 94720, USA.
⁶ Department of Physics, University of California, Berkeley, California 94720, USA and Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.

PMID: 24579636
DOI: 10.1103/PhysRevLett.112.077601

Abstract

We report an observation of long-lived spin-singlet states in a 13C-1H spin pair in a zero magnetic field. In 13C-labeled formic acid, we observe spin-singlet lifetimes as long as 37 s, about a factor of 3 longer than the T1 lifetime of dipole polarization in the triplet state. In contrast to common high-field experiments, the observed coherence is a singlet-triplet coherence with a lifetime T2 longer than the T1 lifetime of dipole polarization in the triplet manifold. Moreover, we demonstrate that heteronuclear singlet states formed between a 1H and a 13C nucleus can exhibit longer lifetimes than the respective triplet states even in the presence of additional spins that couple to the spin pair of interest. Although long-lived homonuclear spin-singlet states have been extensively studied, this is the first experimental observation of analogous singlet states in heteronuclear spin pairs.