Momentum-Resolved Spectroscopy of Superconductivity with the Quantum Twisting Microscope

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Mechanics

Background:

• Superconductivity in two-dimensional (2D) materials is a key area of condensed matter physics research.
• Understanding the pairing symmetry and microscopic mechanisms is crucial for developing new superconducting technologies.

Purpose of the Study:

• To develop a theoretical framework for probing superconductivity with momentum resolution.
• To establish the quantum twisting microscope (QTM) as a direct tool for analyzing superconducting properties.

Main Methods:

• Utilizing a planar tunneling device (QTM) with a rotated graphene tip relative to a 2D sample.
• Leveraging in-plane momentum conservation to measure the superconducting spectral function.
• Analyzing Bogoliubov coherence factors from electron and hole excitation intensities to determine pairing magnitude.

Main Results:

• The QTM directly measures superconducting spectral functions along defined momentum trajectories.
• Relative intensities of excitations reveal momentum-dependent pairing magnitude.
• Detection of rotational symmetry breaking and nodal points in the superconducting order parameter is enabled.

Conclusions:

• The QTM framework provides direct access to pairing symmetry and the microscopic origins of superconductivity.
• The method is applicable to various models, including those with and without electron-electron interactions.
• This establishes the QTM as a powerful tool for studying superconductivity in 2D materials.