Combining electron spin resonance spectroscopy with scanning tunneling microscopy at high magnetic fields

Area of Science:

• Quantum physics
• Materials science
• Nanotechnology

Background:

• Quantum computing and memory technologies require advanced magnetic characterization.
• Current electron spin resonance scanning tunneling microscopy (ESR-STM) is limited by its operational frequency range.
• Many ESR-STM instruments operate within the thermal noise regime, hindering precise spin manipulation.

Purpose of the Study:

• To overcome the frequency limitations of ESR-STM.
• To extend the operational frequency range of ESR-STM to investigate spin dynamics in the high-field limit.
• To enable coherent manipulation and detection of individual quantum spins.

Main Methods:

• Developed a method to extend the operational frequency range of ESR-STM.
• Augmented existing instruments to achieve frequencies up to 100 GHz.
• Utilized inelastic tunneling in a microwave-driven junction for analysis.

Main Results:

• Extended the ESR-STM operational frequency range by over a factor of two, reaching 100 GHz.
• Achieved a regime where Zeeman energy dominates at cryogenic temperatures (few hundred millikelvin).
• Demonstrated proof-of-principle measurements for ESR-STM.

Conclusions:

• The developed method successfully enhances ESR-STM capabilities for high-field spin dynamics studies.
• This advancement is crucial for developing quantum memories and computers.
• The technique provides a general method for augmenting existing instruments for advanced quantum spin investigations.