Magnetic properties of molecules on surfaces studied with scanning probe methods

Area of Science:

• Quantum magnetism and spintronics
• Surface science
• Molecular engineering

Background:

• Magnetic molecules on surfaces serve as platforms for quantum magnetism research.
• Scanning probe techniques enable control and observation of single-molecule spin states and their interactions.
• Phenomena like the Kondo effect and Yu-Shiba-Rusinov states emerge from these systems.

Purpose of the Study:

• To review recent advancements in creating and measuring quantum magnetic properties of molecules on surfaces.
• To summarize methodologies for controlling spin anisotropy, excitations, and correlations.
• To distill design principles for molecular spin devices.

Main Methods:

• Scanning tunneling microscopy (STM)
• Inelastic tunneling spectroscopy (ITS)
• Pump-probe spectroscopy
• Functionalized and superconducting tips
• Magnetic exchange force microscopy (MFM)

Main Results:

• Molecular design, adsorption geometry, and interfacial hybridization enable tunable spin anisotropy, excitations, and correlations.
• Case studies demonstrate control over single-ion magnets, Kondo-active molecules, and coupled spin architectures.
• Design rules for tuning exchange, anisotropy, and charge transfer at the molecule-surface interface have been identified.

Conclusions:

• Significant progress has been made in using molecules on surfaces for quantum magnetism and spintronics.
• Opportunities exist in van der Waals integration, ultrafast spin dynamics, and data-driven spectroscopy.
• Future directions include addressing challenges in reproducibility, room-temperature stability, and multiscale theory for programmable molecular spin devices.