Effect of gate voltage on spin transport alongα-helical protein

Abstract

Recently, the chiral-induced spin selectivity in molecular systems has attracted extensive interest among the scientific communities. Here, we investigate the effect of the gate voltage on spin-selective electron transport through the α-helical peptide/protein molecule contacted by two nonmagnetic electrodes. Based on an effective model Hamiltonian and the Landauer-Büttiker formula, we calculate the conductance and the spin polarization under an external electric field which is perpendicular to the helix axis of the α-helical peptide/protein molecule. Our results indicate that both the magnitude and the direction of the gate field have a significant effect on the conductance and the spin polarization. The spin filtration efficiency can be improved by properly tuning the gate voltage, especially in the case of strong dephasing regime. And the spin polarization increases monotonically with the molecular length without the gate voltage, which is consistent with the recent experiment, and presents oscillating behavior in the presence of the gate voltage. In addition, the spin selectivity is robust against the dephasing, the on-site energy disorder, and the space angle disorder under the gate voltage. Our results could motivate further experimental and theoretical works on the chiral-based spin selectivity in molecular systems.

Localization to delocalization transition in a double stranded helical geometry: effects of conformation, transverse electric field and dynamics

“…t j,i represents the intra-chain hopping integral between the sites n and (n + i), and it becomes 26,41 t j,i = t j,1 e −(lj,i−lj,1)/lc…”

The Influence of Electronic Structure Modelling and Junction Structure on First-Principles Chiral Induced Spin Selectivity

“…While tight-binding and first-principles theoretical descriptions of a related effect, spin splitting in surface states of Au (111) surfaces induced by Rashba SOC, 22 can yield quantitative accuracy, 23,24 such tight-binding [25][26][27][28][29][30][31][32][33][34][35] and first-principles 36,37 descriptions of the CISS effect so far underestimate it by several orders of magnitude. 38,39 It has been suggested that this discrepancy is due to dephasing 25,29 or local leakages, 35 which can be modeled in terms of Büttiker probes.…”

Double-Gated Nanohelix as a Novel Tunable Binary Superlattice

“…In particular, subjecting a nanohelix to a transverse electric field (normal to the helix axis) gives rise to superlattice behaviour such as Bragg scattering of electrons on a super-periodic potential, leading to an energy splitting at the edge of the superlattice Brillouin zone between the lowest states linearly tunable by the electric field [42, 43]. This behaviour may result in Bloch oscillations and negative differential conductance [44, 45], and can emphasize spin-polarized transport through helices [31, 46], as well as yield a circular dichroism enhancement useful in nanophotonic chiroptical applications [47]. This system constitutes a unary superlattice and further opens the possibility to use nanohelices as either tunnel diodes or Gunn diodes for frequency multiplying, amplification, and generation or absorption of radiation in the eulogized terahertz range [48–51].…”