@article{40c60126f38540a590e887dd149c8127,
title = "Electronic Spin Qubit Candidates Arrayed within Layered Two-Dimensional Polymers",
abstract = "Molecular electronic spin qubits are promising candidates for quantum information science applications because they can be reliably produced and engineered via chemical design. Embedding electronic spin qubits within two-dimensional polymers (2DPs) offers the possibility to systematically engineer inter-qubit interactions while maintaining long coherence times, both of which are prerequisites to their technological utility. Here, we introduce electronic spin qubits into a diamagnetic 2DP by n-doping naphthalene diimide subunits with varying amounts of CoCp2 and analyze their spin densities by quantitative electronic paramagnetic resonance spectroscopy. Low spin densities (e.g., 6.0 × 1012 spins mm-3) enable lengthy spin-lattice (T1) and spin-spin relaxation (T2) times across a range of temperatures, ranging from T1 values of 164 ms at 10 K to 30.2 μs at 296 K and T2 values of 2.36 μs at 10 K to 0.49 μs at 296 K for the lowest spin density sample examined. Higher spin densities and temperatures were both found to diminish T1 times, which we attribute to detrimental cross-relaxation from spin-spin dipolar interactions and spin-phonon coupling, respectively. Higher spin densities decreased T2 times and modulated the T2 temperature dependence. We attribute these differences to the competition between hyperfine and dipolar interactions for electron spin decoherence, with the dominant interaction transitioning from the former to the latter as spin density and temperature increase. Overall, this investigation demonstrates that dispersing electronic spin qubits within layered 2DPs enables chemical control of their inter-qubit interactions and spin decoherence times.",
author = "Oanta, {Alexander K.} and Collins, {Kelsey A.} and Evans, {Austin M.} and Pratik, {Saied Md} and Hall, {Lyndon A.} and Strauss, {Michael J.} and Marder, {Seth R.} and D'Alessandro, {Deanna M.} and Tijana Rajh and Freedman, {Danna E.} and Hong Li and Br{\'e}das, {Jean Luc} and Lei Sun and Dichtel, {William R.}",
note = "Funding Information: The Army Research Office is thanked for a Multidisciplinary University Research Initiative (MURI) award under grant W911NF-15-1-0447, which supported the preparation of electroactive 2DPs, characterization, and study using density functional theory. The Department of Energy grant DE-SC0019356 is thanked for supporting efforts at controlled molecular doping, including the investigation of charge transport, electronic structure, and paramagnetic behavior. A.M.E. (DGE-1324585), K.A.C. (DGE-1842165), and M.J.S. (DGE-11842165) were supported by the National Science Foundation Graduate Research Fellowship. A.M.E. is supported by the Schmidt Science Fellows, in partnership with the Rhodes Trust. L.S. was supported by the Laboratory Directed Research and Development (LDRD) funding from Argonne National Laboratory, provided by the Director, Office of Science, of the U.S. Department of Energy under Contract DE-AC02-06CH11357. D.M.D. (ARC FT170100283) gratefully acknowledges the Australian Research Council for funding. Dr. Nicholas Shepherd (University of Sydney) is kindly acknowledged for preliminary electrochemical and UV–vis–NIR spectroelectrochemical measurements. This study made use of IMSERC at Northwestern University, which has received support from the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF NNCI-1542205), the Materials Research Science and Engineering Center (National Science Foundation DMR-1720139), the State of Illinois, and the International Institute for Nanotechnology (IIN). Portions of this work were performed at the DuPont-Northwestern-Dow Collaborative Access Team (DND-CAT) located at Sector 5 and Sector 8 of the Advanced Photon Source (APS). DND-CAT was supported by Northwestern University, E.I. DuPont de Nemours & Co., and the Dow Chemical Company. This research used resources of the Advanced Photon Source and Center for Nanoscale Materials, both U.S. Department of Energy (DOE) Office of Science User Facilities operated for the DOE Office of Science by Argonne National Laboratory under contract DE-AC02-06CH11357, and the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under contract no. DE-AC02-05CH11231. Resources at the Advanced Photon Source were funded by National Science Foundation under award 0960140. The views expressed in the article do not necessarily represent the views of the DOE or the U.S. government. The U.S. government retains, and the publisher, by accepting the article for publication, acknowledges that the U.S. government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this work, or allow others to do so, for U.S. government purposes. Publisher Copyright: {\textcopyright} 2022 American Chemical Society.",
year = "2023",
month = jan,
day = "11",
doi = "10.1021/jacs.2c11784",
language = "English (US)",
volume = "145",
pages = "689--696",
journal = "Journal of the American Chemical Society",
issn = "0002-7863",
publisher = "American Chemical Society",
number = "1",
}