Abstract
The observation of chiral-induced spin selectivity (CISS) in biological molecules still awaits a full theoretical explanation. In a recent Rapid Communication, Varela et al. [Phys. Rev. B 101, 241410(R) (2020)] presented a model for electron transport in biological molecules by tunneling in the presence of spin-orbit interactions. They then claimed that their model produces a strong spin asymmetry due to the intrinsic atomic spin-orbit strength. As their Hamiltonian is time-reversal symmetric, this result contradicts a theorem by Bardarson [J. Phys. A: Math. Theor. 41, 405203 (2008)], which states that such a Hamiltonian cannot generate a spin asymmetry for tunneling between two terminals (in which there are only a spin-up and a spin-down channel). Here we solve the model proposed by Varela et al. and show that it does not yield any spin asymmetry, and therefore cannot explain the observed CISS effect.
- Received 22 July 2020
- Revised 8 September 2020
- Accepted 25 January 2021
DOI:https://doi.org/10.1103/PhysRevB.103.077401
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