Theory of Atomic-Scale Direct Thermometry Using Electron Spin Resonance via Scanning Tunneling Microscopy

Area of Science:

• Condensed Matter Physics
• Quantum Sensing
• Nanoscale Science

Background:

• Temperature measurement at the nanoscale is crucial for understanding various physical phenomena.
• Existing methods face limitations in resolution and applicability at low temperatures.
• Two-level systems offer a potential pathway for direct temperature readout via occupation ratios.

Purpose of the Study:

• To theoretically investigate the precision and capabilities of Electron Spin Resonance via Scanning Tunneling Microscopy (ESR-STM) for nanoscale thermometry.
• To analyze the influence of noise and spin geometry on thermometry performance.
• To assess the potential for detecting minute thermal gradients.

Main Methods:

• Theoretical modeling of a two-level magnetic atom system coupled to ESR-STM.
• Analysis of energy splitting and occupation ratios for temperature determination.
• Incorporation of shot noise, back-action, and spin geometry effects into the theoretical framework.

Main Results:

• Predicted ESR-STM thermometry resolution of 10 mK at approximately 1 K.
• Demonstrated capability to detect thermal gradients as small as 5 mK/nm.
• Identified the significant role of spin geometry in improving the signal-to-noise ratio.

Conclusions:

• ESR-STM provides a promising route for high-resolution nanoscale thermometry.
• The theoretical framework elucidates key factors influencing measurement precision.
• This technique offers new avenues for localized temperature measurements in quantum devices and materials.