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arXiv · 2212.13376

Scanning tunneling microscopy study of hidden phases in atomically thin 1T-TaS$_2$

Wooin Yang·Dowook Kim·Hyoung Kug Kim·Tae-Hwan Kim
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Abstract

Lower thermal stability due to thinning often leads to unprecedented hidden phases in low-dimensional materials. Such hidden phases can coexist or compete with preexisting electronic phases. We investigate hidden phases observed in atomically thin (6-8 layers) 1T-TaS$_2$ with scanning tunneling microscopy. First, we can electrically induce a hidden stripe phase at room temperature. Such a uniaxial stripe phase has three equivalent orientations by breaking three-fold symmetry of 1T-TaS$_2$. We also reveal that the hidden stripe phase coexists with nearly commensurate charge-density-wave phase. Next, we observe that the emergent stripe phase spontaneously appears without any electric excitation on a tiny flake ($160\times80$ nm$^2$). Our findings may provide a plausible explanation for the previously observed phase transition and two-fold optical response in thin 1T-TaS$_2$ devices at room temperature. Furthermore, the hidden stripe phase would be crucial to understand exotic CDW-related phenomena in 1T-TaS$_2$ for potential applications.

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Wooin Yang, Dowook Kim, Hyoung Kug Kim, Tae-Hwan Kim. 2022-12-27. Scanning tunneling microscopy study of hidden phases in atomically thin 1T-TaS$_2$. https://doi.org/10.1007/s40042-023-00705-0

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