nl0c01607_si_001.pdf (6.9 MB)
Pseudogap and Weak Multifractality in 2D Disordered Mott Charge-Density-Wave Insulator
journal contribution
posted on 2020-08-06, 22:01 authored by Jianhua Gao, Jae Whan Park, Kiseok Kim, Sun Kyu Song, Hae Ryong Park, Jhinhwan Lee, Jewook Park, Fangchu Chen, Xuan Luo, Yuping Sun, Han Woong YeomWe
investigate electronic states of Se-substituted 1T-TaS2 by scanning tunneling microscopy/spectroscopy (STM/STS),
where superconductivity emerges from the unique Mott-charge-density-wave
(Mott-CDW) state. Spatially resolved STS measurements reveal that
a pseudogap replaces the Mott gap with the CDW gaps intact. The pseudogap
has little correlation with the unit-cell-to-unit-cell variation in
the local Se concentration but appears globally. The correlation length
of the local density of states (LDOS) is substantially enhanced at
the Fermi energy and decays rapidly at high energies. Furthermore,
the statistical analysis of LDOS indicates the weak multifractal behavior
of the wave functions. These findings suggest a correlated metallic
state induced by disorder and provide a new insight into the emerging
superconductivity in two-dimensional materials.