TY - JOUR
T1 - Spin-orbit interaction and spin selectivity for tunneling electron transfer in DNA
AU - Varela, Solmar
AU - Zambrano, Iskra
AU - Berche, Bertrand
AU - Mujica, Vladimiro
AU - Medina, Ernesto
N1 - Funding Information:
This work was supported by CEPRA VIII Grant No. XII-2108-06, Mechanical Spectroscopy funded by CEDIA, Ecuador. V.M. acknowledges a Fellowship from Ikerbasque, the Basque Foundation for Science. We acknowledge useful discussions with J. Svozilík.
PY - 2020/6/15
Y1 - 2020/6/15
N2 - Electron transfer (ET) in biological molecules, such as peptides and proteins, consists of electrons moving between well-defined localized states (donors to acceptors) through a tunneling process. Here, we present an analytical model for ET by tunneling in DNA in the presence of spin-orbit (SO) interaction to produce a strong spin asymmetry with the intrinsic atomic SO strength in the meV range. We obtain a Hamiltonian consistent with charge transport through π orbitals on the DNA bases and derive the behavior of ET as a function of the injection state momentum, the spin-orbit coupling, and barrier length and strength. Both tunneling energies, deep below the barrier and close to the barrier height, are considered. A highly consistent scenario arises where two concomitant mechanisms for spin selection arises; spin interference and differential spin amplitude decay. High spin filtering can take place at the cost of reduced amplitude transmission assuming realistic values for the SO coupling. The spin filtering scenario is completed by addressing the spin-dependent torque under the barrier with a consistent conserved definition for the spin current.
AB - Electron transfer (ET) in biological molecules, such as peptides and proteins, consists of electrons moving between well-defined localized states (donors to acceptors) through a tunneling process. Here, we present an analytical model for ET by tunneling in DNA in the presence of spin-orbit (SO) interaction to produce a strong spin asymmetry with the intrinsic atomic SO strength in the meV range. We obtain a Hamiltonian consistent with charge transport through π orbitals on the DNA bases and derive the behavior of ET as a function of the injection state momentum, the spin-orbit coupling, and barrier length and strength. Both tunneling energies, deep below the barrier and close to the barrier height, are considered. A highly consistent scenario arises where two concomitant mechanisms for spin selection arises; spin interference and differential spin amplitude decay. High spin filtering can take place at the cost of reduced amplitude transmission assuming realistic values for the SO coupling. The spin filtering scenario is completed by addressing the spin-dependent torque under the barrier with a consistent conserved definition for the spin current.
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U2 - 10.1103/PhysRevB.101.241410
DO - 10.1103/PhysRevB.101.241410
M3 - Article
AN - SCOPUS:85086994519
VL - 101
JO - Physical Review B
JF - Physical Review B
SN - 2469-9950
IS - 24
M1 - 241410
ER -