Abstract
Paradigmatic quantum spin liquid has been in the past closely linked to the high-temperature superconductivity. Here we focus on a layered 1T-, which has recently emerged as a surprising candidate for a quantum spin liquid on a triangular lattice. Upon doping 1T- with Se, the nuclear magnetic resonance and nuclear quadrupole resonance data show a remarkable robustness of the quantum spin liquid at low Se doping levels despite the growth of inhomogeneities in the electronic state. A dramatic change in the low-energy electronic excitations are observed in samples with a moderate Se content where the Mott insulating state gives way to a correlated metal and a low-temperature superconductivity. The effects of antiferromagnetic correlations can still be traced in the normal state above the superconducting critical temperature and may, together with the underlying disorder, account for the large superconducting gap-to- ratio deduced from the scanning tunneling microscopy.
- Received 13 May 2020
- Revised 10 July 2020
- Accepted 13 July 2020
DOI:https://doi.org/10.1103/PhysRevB.102.054401
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