Nanoscale Imaging of Current Density with a Single-Spin Magnetometer

Area of Science:

• Condensed Matter Physics
• Materials Science
• Nanotechnology

Background:

• Charge transport in nanostructures is crucial for quantum effects, electronic circuits, and energy research.
• Direct visualization of nanoscale current flow is difficult due to size limitations and the nature of charge carriers.

Purpose of the Study:

• To demonstrate a noninvasive method for imaging current density in two-dimensional conductor networks.
• To enable detailed study of electronic transport properties in nanomaterials.

Main Methods:

• Utilized a scanning tip with a diamond nitrogen-vacancy (NV) center as a sensor.
• Employed a differential measurement technique under ambient conditions.
• Achieved current density imaging with high spatial resolution (down to 22 nm).

Main Results:

• Successfully imaged current density in metallic nanowires and carbon nanotubes.
• Detected DC currents as low as a few microamperes (μA).
• Established a current density noise floor of approximately 2 × 10^4 A/cm^2.

Conclusions:

• Current density imaging provides a novel approach for analyzing electronic transport in 2D materials.
• This technique offers significant potential for advancing condensed matter physics and materials science research.
• The method is applicable to various nanoscale devices and conductive networks.