Mechanism of spin polarization from spin-blind decoherence in CISS

Determine the specific physical mechanism by which spin-independent (spin-blind) decoherence generates a nonzero spin polarization in electron transport through chiral molecules with atomic spin–orbit coupling in the chirally induced spin selectivity (CISS) regime under conditions where time-reversal symmetry is broken by environmental coupling rather than by magnetic fields.

Background

A central challenge in explaining CISS within two-terminal linear-response setups is that reciprocity forbids spin polarization when time-reversal symmetry holds. Decoherence has been proposed as a generic way to break time-reversal symmetry without invoking magnetic fields, making spin filtering possible in principle.

Despite this symmetry-based rationale, the microscopic route by which spin-independent dephasing processes yield net spin polarization is not evident. The authors highlight this gap and motivate analyses that combine decoherence with tunneling and spin–orbit coupling to account for the observed magnitudes of polarization.