Kondo tunneling through real and artificial molecules

Area of Science:

• Quantum Condensed Matter Physics
• Mesoscopic Physics
• Molecular Electronics

Background:

• Asymmetric double quantum dots exhibit complex electronic behaviors when hybridized with itinerant electrons.
• The interplay between singlet-triplet splitting and the Kondo effect governs their low-energy properties.

Purpose of the Study:

• To investigate the competition between the Zhang-Rice mechanism and the Kondo effect in asymmetric double dots.
• To explore the physics of an underscreened S = 1 Kondo impurity with low-lying triplet-singlet excitations.
• To present estimates for magnetic susceptibility and electric conductance.

Main Methods:

• Theoretical modeling of quantum dot systems.
• Analysis of electron tunneling under Coulomb blockade.
• Investigation of magnetic susceptibility and electric conductance.

Main Results:

• The study reveals a crossing of singlet ground and triplet excited states.
• It exposes the rich physics of an underscreened S = 1 Kondo impurity.
• Estimates for magnetic susceptibility and electric conductance are provided.

Conclusions:

• The findings offer insights into the fundamental physics of interacting quantum dots.
• The research has potential applications in molecule chemisorption on metallic substrates.
• This work contributes to the understanding of quantum impurity phenomena.