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Quantum indistinguishability in chemical reactions

Fisher, Matthew P. A. and Radzihovsky, Leo (2018) Quantum indistinguishability in chemical reactions. Proceedings of the National Academy of Sciences of the United States of America, 115 (20). E4551-E4558. ISSN 0027-8424. PMCID PMC5960291. doi:10.1073/pnas.1718402115.

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Quantum indistinguishability plays a crucial role in many low-energy physical phenomena, from quantum fluids to molecular spectroscopy. It is, however, typically ignored in most high-temperature processes, particularly for ionic coordinates, implicitly assumed to be distinguishable, incoherent, and thus well approximated classically. We explore enzymatic chemical reactions involving small symmetric molecules and argue that in many situations a full quantum treatment of collective nuclear degrees of freedom is essential. Supported by several physical arguments, we conjecture a “quantum dynamical selection” (QDS) rule for small symmetric molecules that precludes chemical processes that involve direct transitions from orbitally nonsymmetric molecular states. As we propose and discuss, the implications of the QDS rule include (i) a differential chemical reactivity of para- and orthohydrogen, (ii) a mechanism for inducing intermolecular quantum entanglement of nuclear spins, (iii) a mass-independent isotope fractionation mechanism, (iv) an explanation of the enhanced chemical activity of “reactive oxygen species”, (v) illuminating the importance of ortho-water molecules in modulating the quantum dynamics of liquid water, and (vi) providing the critical quantum-to-biochemical linkage in the nuclear spin model of the (putative) quantum brain, among others.

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Radzihovsky, Leo0000-0002-2281-0835
Additional Information:© 2018 The Author(s). Published under the PNAS license. Contributed by Matthew P. A. Fisher, March 26, 2018 (sent for review October 23, 2017; reviewed by Eduardo Fradkin and Ashvin Vishwanath) We are deeply indebted and most grateful to Stuart Licht for general discussions on this topic and especially for emphasizing the importance of oxygen isotope fractionation experiments to access the (putative) role of nuclear spins in the enzymatic hydrolysis of pyrophosphate, which we discussed in Conceptual and Experimental Implications, QDS Mass-Independent Mechanism for Isotope Fractionation. We also thank Jason Alicea, Leon Balents, Maissam Barkeshli, Steve Girvin, Victor Gurarie, Andreas Ludwig, Lesik Motrunich, Michael Mulligan, David Nesbitt, Nick Read, T. Senthil, Michael Swift, Ashvin Vishwanath, and Mike Zaletel for their patience and input on our work. M.P.A.F.’s research was supported in part by the National Science Foundation (NSF) under Grant DMR-14-04230 and by the Caltech Institute of Quantum Information and Matter, an NSF Physics Frontiers Center with support from the Gordon and Betty Moore Foundation. M.P.A.F. is grateful to the Heising-Simons Foundation for support. L.R. was supported by the Simons Investigator Award from the Simons Foundation, by the NSF under Grant DMR-1001240, by the NSF Material Research Science and Engineering Center Grant DMR-1420736, and by the Kavli Institute for Theoretical Physics (KITP) under Grant NSF PHY-1125915. L.R. thanks the KITP for its hospitality as part of the Synthetic Matter workshop and sabbatical program. Author contributions: M.P.A.F. and L.R. designed research; M.P.A.F. and L.R. performed research; M.P.A.F. analyzed data; and M.P.A.F. and L.R. wrote the paper. Reviewers: E.F., University of Illinois at Urbana–Champaign; and A.V., Harvard University. The authors declare no conflict of interest.
Group:Institute for Quantum Information and Matter
Funding AgencyGrant Number
Institute for Quantum Information and Matter (IQIM)UNSPECIFIED
Gordon and Betty Moore FoundationUNSPECIFIED
Heising-Simons FoundationUNSPECIFIED
Simons FoundationUNSPECIFIED
Kavli Institute for Theoretical PhysicsUNSPECIFIED
Subject Keywords:quantum chemical reactions | quantum indistinguishability | nuclear spin coherence | Berry phases in chemical reactions
Issue or Number:20
PubMed Central ID:PMC5960291
Record Number:CaltechAUTHORS:20180430-145931994
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Official Citation:Quantum indistinguishability in chemical reactions Matthew P. A. Fisher, Leo Radzihovsky Proceedings of the National Academy of Sciences May 2018, 115 (20) E4551-E4558; DOI: 10.1073/pnas.1718402115
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:86142
Deposited By: George Porter
Deposited On:30 Apr 2018 22:49
Last Modified:15 Nov 2021 20:35

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