Open AccessSynthetic Approach To Determine the Effect of Nuclear Spin Distance on Electronic Spin Decoherence
Author(s) -
M. J. Graham,
Chung-Jong Yu,
Matthew D. Krzyaniak,
Michael R. Wasielewski,
Danna E. Freedman
Publication year - 2017
Publication title -
journal of the american chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.115
H-Index - 612
eISSN - 1520-5126
pISSN - 0002-7863
DOI - 10.1021/jacs.6b13030
Subject(s) - chemistry , spin (aerodynamics) , quantum decoherence , spins , spin engineering , electron paramagnetic resonance , endohedral fullerene , pulsed epr , qubit , coherence (philosophical gambling strategy) , atomic physics , condensed matter physics , spin echo , quantum mechanics , quantum , physics , molecule , electron , spin polarization , medicine , organic chemistry , radiology , magnetic resonance imaging , thermodynamics
Nuclear-electronic interactions are a fundamental phenomenon which impacts fields from magnetic resonance imaging to quantum information processing (QIP). The realization of QIP would transform diverse areas of research including accurate simulation of quantum dynamics and cryptography. One promising candidate for the smallest unit of QIP, a qubit, is electronic spin. Electronic spins in molecules offer significant advantages with regard to QIP, and for the emerging field of quantum sensing. Yet relative to other qubit candidates, they possess shorter superposition lifetimes, known as coherence times or T 2 , due to interactions with nuclear spins in the local environment. Designing complexes with sufficiently long values of T 2 requires an understanding of precisely how the position of nuclear spins relative to the electronic spin center affects decoherence. Herein, we report the first synthetic study of the relationship between nuclear spin-electron spin distance and decoherence. Through the synthesis of four vanadyl complexes, (Ph 4 P) 2 [VO(C 3 H 6 S 2 ) 2 ] (1), (Ph 4 P) 2 [VO(C 5 H 6 S 4 ) 2 ] (2), (Ph 4 P) 2 [VO(C 7 H 6 S 6 ) 2 ] (3), and (Ph 4 P) 2 [VO(C 9 H 6 S 8 ) 2 ] (4), we are able to synthetically place a spin-laden propyl moiety at well-defined distances from an electronic spin center by employing a spin-free carbon-sulfur scaffold. We interrogate this series of molecules with pulsed electron paramagnetic resonance (EPR) spectroscopy to determine their coherence times. Our studies demonstrate a sharp jump in T 2 when the average V-H distance is decreased from 6.6(6) to 4.0(4) Å, indicating that spin-active nuclei sufficiently close to the electronic spin center do not contribute to decoherence. These results illustrate the power of synthetic chemistry in elucidating the fundamental mechanisms underlying electronic polarization transfer and provide vital principles for the rational design of long-coherence electronic qubits.