One-dimensional Luttinger liquids in a two-dimensional moiré lattice

Area of Science:

• Condensed matter physics
• Quantum materials
• Materials science

Background:

• The Luttinger liquid (LL) model describes one-dimensional (1D) electronic systems and strongly correlated phenomena like spin-charge separation.
• Extending LL physics to two dimensions (2D) using coupled 1D quantum wires is a key theoretical goal.
• Experimental realization of high-quality 1D LL arrays has been a significant challenge.

Purpose of the Study:

• To experimentally realize 2D arrays of 1D LLs with crystalline quality.
• To investigate the potential of moiré superlattices for creating novel quantum electronic states.
• To explore the feasibility of coupled-wire models in 2D anisotropic systems.

Main Methods:

• Fabrication of moiré superlattices using twisted bilayer tungsten ditelluride (tWTe2).
• Utilizing the inherent anisotropy of tWTe2 to create parallel 1D electronic channels.
• Transport measurements to probe electronic properties and anisotropy at specific twist angles.

Main Results:

• Successful experimental realization of 2D arrays of 1D LLs in tWTe2 moiré superlattices.
• Observation of exceptionally large transport anisotropy (resistance ratio ~1000) in hole-doped tWTe2 at a 5-degree twist angle.
• Power-law scaling in across-wire conductance, consistent with a 2D anisotropic LL array.

Conclusions:

• The study demonstrates a viable platform for realizing 2D arrays of 1D LLs.
• This provides an experimental avenue for exploring coupled-wire models and LL physics in 2D.
• Opens possibilities for discovering novel correlated and topological quantum phases.