Beyond the Landau Fermi liquid paradigm, non-Fermi liquid behavior stands as the cornerstone of deciphering emergent phenomena in strongly correlated quantum systems. In one-dimensional (1D) systems, the Tomonaga-Luttinger liquid (TLL) theory predicts exotic collective excitations and spin-charge separation, yet its experimental realization within ordered electronic phases [e.g., charge density waves (CDWs)] has long remained a key challenge. Here, we report direct spectroscopic visualization of intrinsic TLL behavior in monolayer $1T-\mathrm{VS}{\mathrm{e}}_2$ grown on bilayer graphene, where spontaneously self-organized CDW domain walls (CDW-DWs) emerge as quasi-1D quantum channels embedded within the two-dimensional host. Low-temperature scanning tunneling microscopy/spectroscopy combined with density functional theory calculations reveals definitive signatures of TLL physics, a power-law suppression of the local density of states near the Fermi level with a characteristic exponent $\alpha \approx 0.65$, and spatially resolved electronic features matching quasi-one-dimensional non-Fermi-liquid behavior described by TLL theory. Remarkably, these non-Fermi liquid features persist up to 77 K (liquid nitrogen temperature), a marked advancement over typical TLL systems, reflecting an unusually high energy scale of electron correlations in the CDW-DWs. Supported by analytical modeling incorporating substrate screening effects, our analysis rules out conventional explanations (e.g., single-particle scattering, Peierls distortions) and confirms that the observed spectral gap originates from collective 1D correlation effects. These findings establish CDW-DWs in $\mathrm{VS}{\mathrm{e}}_2$ as a robust, tunable platform for realizing correlated 1D quantum states in van der Waals materials, opening avenues for exploring exotic non-Fermi liquid phases and designing low-dimensional quantum devices.

Close

PrevNext

View figure in article

• Charge density waves
• Strongly correlated systems
• Density functional calculations
• Luttinger liquid model
• Scanning tunneling microscopy
• Scanning tunneling spectroscopy