Odd-Integer Quantum Hall States and Giant Spin Susceptibility in p-Type Few-Layer WSe_{2}

Area of Science:

• Condensed Matter Physics
• Materials Science
• 2D Materials

Background:

• Few-layer tungsten diselenide (WSe_{2}) is a promising 2D material for electronic applications.
• Understanding its electronic properties under magnetic fields is crucial for device development.

Purpose of the Study:

• To investigate the quantum Hall (QH) effect in high-mobility p-type few-layer WSe_{2} transistors.
• To explore the role of magnetic field orientation and exchange interactions.

Main Methods:

• Fabrication of p-type few-layer WSe_{2} field-effect transistors.
• Measurement of quantum Hall states under moderate magnetic fields.
• Tilting the magnetic field to study Landau level crossing effects.

Main Results:

• Observation of an unconventional QH state sequence dominated by odd-integer states.
• Discovery of Landau level crossings at ultralow angles.
• Zeeman energy found to be approximately 3 times the cyclotron energy near the valence band top at the Γ valley.
• Evidence for significant exchange interactions and potential QH ferromagnetism.

Conclusions:

• The Γ valley in few-layer WSe_{2} hosts heavy hole carriers and an enhanced g factor.
• This system serves as a unique platform for exploring strongly correlated phenomena.
• Exchange interactions play a significant role in the observed quantum phenomena.