MOIRE SUPERCONDUCTOR : SCIENCE & TECHNOLOGY

NEWS: New moiré superconductor opens the door to new quantum materials

WHAT’S IN THE NEWS?

Moiré materials, formed by twisting 2D layers like graphene, exhibit unique properties, including superconductivity. Recent research on twisted bilayer tungsten diselenide (tWSe₂) reveals robust superconductivity driven by electron-electron interactions, expanding possibilities for semiconductor-based superconductors.

Moiré Materials and Twisted Bilayer Tungsten Diselenide (tWSe₂)

Introduction to Moiré Materials:

  • Formed by stacking two 2D material layers, such as graphene, and twisting one layer slightly.
  • Exhibits unique electronic and quantum properties, including superconductivity.

Semiconductor Moiré Materials and Superconductivity:

  • Recent research shows twisted bilayer tungsten diselenide (tWSe₂), a semiconductor-based moiré material, exhibits superconductivity.
  • Challenges the prior assumption that superconductivity in moiré materials is exclusive to graphene.

Moiré Pattern and Flat Bands:

  • Twisting creates a moiré pattern, altering the electronic structure and forming flat bands.
  • Flat bands lead to uniform electron energies, enabling strong electron-electron interactions and the formation of Cooper pairs, essential for superconductivity.

Key Findings on tWSe₂:

  • Transitions to a superconducting state at –272.93°C (near absolute zero).
  • Superconductivity arises from electron-electron interactions at half-filled electronic states, differing from graphene-based systems.
  • Displays a long coherence length, 10 times greater than other moiré materials.
  • Also transitions to an insulating state under specific electronic conditions.

Implications:

  • Demonstrates the stability of tWSe₂’s superconducting state and its potential for semiconductor-based superconductor applications.
  • Enhances understanding of how twisting 2D layers impacts electronic structure and superconductivity.