Spin-dependent transport through a chiral molecule in the presence of spin-orbit interaction and nonunitary effects

Shlomi Matityahu, Yasuhiro Utsumi, Amnon Aharony, Ora Entin-Wohlman, Carlos A. Balseiro

Research output: Contribution to journalArticlepeer-review

108 Scopus citations


Recent experiments have demonstrated the efficacy of chiral helically shaped molecules in polarizing the scattered electron spin, an effect termed chiral-induced spin selectivity. Here we solve a simple tight-binding model for electron transport through a single helical molecule, with spin-orbit interactions on the bonds along the helix. Quantum interference is introduced via additional electron hopping between neighboring sites in the direction of the helix axis. When the helix is connected to two one-dimensional single-mode leads, time-reversal symmetry prevents spin polarization of the outgoing electrons. One possible way to retrieve such a polarization is to allow leakage of electrons from the helix to the environment, via additional outgoing leads. Technically, the leakage generates complex site self-energies, which break unitarity. As a result, the electron waves in the helix become evanescent, with different decay lengths for different spin polarizations, yielding a net spin polarization of the outgoing electrons, which increases with the length of the helix (as observed experimentally). A maximal polarization can be measured at a finite angle away from the helix axis.

Original languageEnglish
Article number075407
JournalPhysical Review B
Issue number7
StatePublished - 2 Feb 2016


FundersFunder number
Japan Society for the Promotion of Science26400390, 26220711


    Dive into the research topics of 'Spin-dependent transport through a chiral molecule in the presence of spin-orbit interaction and nonunitary effects'. Together they form a unique fingerprint.

    Cite this