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Accepted · first revision · record

Title: Why chiral molecules polarize electron spins so strongly
Plain: Measured spin polarizations through chiral molecules reach tens of percent. The relativistic effect that links spin to motion, spin-orbit coupling, is only a few milli-electronvolts (a tiny energy) in carbon, which predicts effects hundreds of times smaller.
Precise: Explain spin polarizations P of 10 to 60 percent reported in photoemission through chiral monolayers and in magnetoconductance of chiral molecular junctions, given atomic spin-orbit coupling constants of about 3 meV (C) to 20 meV (O), and much smaller effective couplings in the molecular orbitals. An answer is a microscopic mechanism with no fitted parameters that reproduces P, its sign versus handedness, and its dependence on molecular length and temperature.
Settled by: A first-principles theory reproducing quantitative CISS data on a benchmark system measured consistently in several laboratories.
Kind: phenomenon
Answer type: mechanism
References: (empty)
Literature status: contested
Status note: Reviews from 2022 to 2024 report that realistic single-particle spin-orbit models give at most a few percent polarization and no mechanism is accepted.
Posed since: 1999