CHEM In the literature: contested

Why chiral molecules polarize electron spins so strongly

In plain words

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 statement

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.

What would settle it

A first-principles theory reproducing quantitative CISS data on a benchmark system measured consistently in several laboratories.

Status in the literature

Unverified 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.

Related problems

See also