Weak Electron-Phonon Coupling Is Insufficient to Generate Significant CISS in Two-Terminal Transport

Abstract

A central open question in chiral-induced spin selectivity (CISS) is whether weak electron-phonon coupling in a helical molecular junction can generate a sizable spin polarization in two-terminal transport without invoking additional strong symmetry-breaking ingredients. We address this question by implementing a self-consistent nonequilibrium Green's function (NEGF) calculation for a helical tight-binding model with spin-orbit coupling and electron-phonon interactions. The electron-phonon self-energies are evaluated self-consistently, and the transport signal is extracted using the standard magnetization-reversal protocol with a spin-polarized analyzer lead. We benchmark a fully self-consistent NEGF within the self-consistent Born approximation (SCBA) treatment for both global and local electron-phonon couplings against commonly used approximations, including diagonal self-energy schemes. We quantify how the resulting transport regime and spin polarization depend on phonon frequency, coupling strength, bias, temperature, and system size. In contrast to large polarizations and anomalous size trends reported under approximate treatments, the fully self-consistent calculation yields negligible spin polarization, additionally the electron-phonon coupling mainly renormalizes the spectrum, and transport remains quasi-ballistic across the explored parameter range.

15 pages, 5 figures

References in corpus (25)

• Molecular Transport Junctions: Vibrational Effects
• Inelastic transport theory from first-principles: methodology and applications for nanoscale devices
• Spin-Selective Transport of Electron in DNA Double Helix
• Spin selective transport through helical molecular systems
• Modeling inelastic phonon scattering in atomic- and molecular-wire junctions
• Vibrational Origin of Exchange Splitting and Chirality Induced Spin Selectivity
• Chirality Induced Spin Selectivity -- The Role of Electron Correlations
• Non-equilibrium Green s function based model for dephasing in quantum transport
• Non-equilibrium Green's function formalism and the problem of bound states
• A proof of the Kramers degeneracy of transmission eigenvalues from antisymmetry of the scattering matrix
• Spin selectivity through time-reversal symmetric helical junctions
• Spin Polarization through A Molecular Junction Based on Nuclear Berry Curvature Effects
• Exploring the limits of the self consistent Born approximation for inelastic electronic transport
• Interplay between friction and spin-orbit coupling as a source of spin polarization
• The Chiral Induced Spin Selectivity Effect -- What It Is, What It Is Not, And Why It Matters
• Chirality-Induced Spin Filtering in Pseudo Jahn-Teller Molecules
• Many-Body Models for Chirality-Induced Spin Selectivity in Electron Transfer
• Temperature-dependence of the chirality-induced spin selectivity effect -- experiments and theory
• Chiral induced Spin Polarized Electron Current: Origin of the Chiral Induced Spin Selectivity Effect
• Universal subdiffusive behavior at band edges from transfer matrix exceptional points
• Electric field-induced nonreciprocal spin current due to chiral phonons in chiral-structure superconductors
• The spinterface mechanism for the chiral-induced spin selectivity effect: A Critical Perspective
• Should it really be that hard to model the chirality induced spin selectivity effect?
• Spin-orbit interactions, time-reversal symmetry, and spin selection
• Breaking of Time-Reversal Symmetry and Onsager Reciprocity in Chiral Molecule Interfacd with an Environment