Cryptochromes are blue light photorecep-tors that mediate key biological processes through photoinduced electron transfer(ET).We present a theoretical study of the second ET step along the conserved trypto-phan triad ...Cryptochromes are blue light photorecep-tors that mediate key biological processes through photoinduced electron transfer(ET).We present a theoretical study of the second ET step along the conserved trypto-phan triad in Arabidopsis thaliana cryp-tochrome,focusing on how vibrational envi-ronments affect the ultrafast electron trans-fer.Using the numerically exact low temper-ature quantum Fokker-Planck equation(LT-QFPE)within the hierarchical equations of motion(HEOM)framework,we resolve the contributions of individual Brownian oscillator modes:low frequency modes with large reorganization energies markedly reduce the ET rate,whereas weakly damped high frequency modes generate oscillations linked to electronic-vibra-tional coherence.The LT-QFPE results are also used to benchmark three second order pertur-bative methods:the non-equilibrium Fermi’s golden rule(NE-FGR),non-interacting blip ap-proximation(NIBA),and the time local generalized quantum master equation.Although all approximate methods reproduce correct long-time ET rates,they fail to capture short time non-equilibrium dynamics.These findings clarify how spectral width and bath correlation time,in addition to total reorganization energy,govern the validity of perturbative treat-ments and highlight the need for numerically exact methods such as HEOM in modeling non-equilibrium cryptochrome ET dynamics.s.展开更多
基金supported by the National Natural Science Foundation of China(No.22433006).
文摘Cryptochromes are blue light photorecep-tors that mediate key biological processes through photoinduced electron transfer(ET).We present a theoretical study of the second ET step along the conserved trypto-phan triad in Arabidopsis thaliana cryp-tochrome,focusing on how vibrational envi-ronments affect the ultrafast electron trans-fer.Using the numerically exact low temper-ature quantum Fokker-Planck equation(LT-QFPE)within the hierarchical equations of motion(HEOM)framework,we resolve the contributions of individual Brownian oscillator modes:low frequency modes with large reorganization energies markedly reduce the ET rate,whereas weakly damped high frequency modes generate oscillations linked to electronic-vibra-tional coherence.The LT-QFPE results are also used to benchmark three second order pertur-bative methods:the non-equilibrium Fermi’s golden rule(NE-FGR),non-interacting blip ap-proximation(NIBA),and the time local generalized quantum master equation.Although all approximate methods reproduce correct long-time ET rates,they fail to capture short time non-equilibrium dynamics.These findings clarify how spectral width and bath correlation time,in addition to total reorganization energy,govern the validity of perturbative treat-ments and highlight the need for numerically exact methods such as HEOM in modeling non-equilibrium cryptochrome ET dynamics.s.
