Electron transport through a spin crossover junction. Perspectives from a wavefunction-based approach.

Area of Science:

• Computational chemistry
• Molecular electronics
• Spintronics

Background:

• Electron transport in molecular junctions is key to developing novel electronic devices.
• Spin crossover molecular systems offer tunable electronic properties.
• Accurate theoretical modeling is essential for understanding and designing these systems.

Purpose of the Study:

• To apply a computational framework based on quantum master equation and Fermi's golden Rule to electron transport in a spin crossover molecular junction.
• To evaluate the junction's Green's function using accurate state energies and wavefunctions.
• To analyze the contribution of various electronic states to current and conductivity.

Main Methods:

• Utilized a computational framework combining quantum master equation, Fermi's golden Rule, and wavefunction-based methods.
• Calculated state energies and wavefunctions for high- and low-spin species of the Fe(bapbpy)(NCS)2 molecule.
• Evaluated output conductance across a range of bias- and gate-voltages, analyzing contributions from ground and excited states.

Main Results:

• The computational framework accurately describes electron transport through the spin crossover molecular junction.
• Considering the full spectrum of low-energy states, not just the ground state, significantly impacts total conductivity.
• The improved model restores equivalence between spin-up and spin-down transport, showing no spin polarization without Zeeman splitting.

Conclusions:

• The developed theoretical framework provides a more accurate representation of electron transport in molecular junctions.
• Accurate modeling of all relevant molecular states is crucial for predicting conductivity and spin properties.
• This work offers new insights into molecular switchable materials and spintronics.