Nanoironing van der Waals Heterostructures toward Electrically Controlled Quantum Dots

Area of Science:

• Condensed Matter Physics
• Materials Science
• Nanotechnology

Background:

• Two-dimensional van der Waals (vdW)-layered materials enable the creation of heterostructures with unique correlated electronic properties.
• vdW heterostructures hold promise for advanced applications in optoelectronics, valleytronics, spintronics, and quantum technology.
• Achieving the full potential of vdW heterostructures is hindered by the challenge of engineering interfaces with minimal disorder.

Purpose of the Study:

• To introduce a novel method for creating pristine interfaces in vdW heterostructures.
• To demonstrate the material- and device-level compatibility of the proposed technique.
• To showcase the application of low-disorder interfaces in the electrical formation and control of quantum dots.

Main Methods:

• Utilized thermal scanning probes to engineer interfaces in vdW heterostructures.
• Fabricated and characterized monolayer tungsten disulfide (WS2) transistors.
• Investigated the electrical properties of vdW heterostructures for quantum dot formation.

Main Results:

• The thermal scanning probe technique successfully created exceptionally low-disorder interfaces.
• Monolayer WS2 transistors fabricated using this method exhibited up to an order of magnitude improvement in electrical performance.
• Demonstrated the ability to electrically form and tune quantum dots within low-disorder vdW heterostructures, spanning from macroscopic current to single-electron tunneling.

Conclusions:

• Thermal scanning probe microscopy is an effective technique for fabricating high-quality interfaces in vdW heterostructures.
• This approach significantly enhances the performance of 2D material-based devices, such as WS2 transistors.
• The developed low-disorder interfaces are crucial for realizing advanced quantum devices, including tunable quantum dots.