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The bulk heterostructure 6R-TaS$_{2}$ offers a unique platform to study the interplay of charge density waves, superconductivity, and electronic transport anomalies. Notably, nematic Ising superconductivity has been recently proposed, and a hidden order accompanied by a large anomalous Hall effect at $T^{*}$ ${\simeq}$ 35 K has been identified, raising fundamental questions about the nature of superconducting pairing and its connection to CDW order and the AHE. Using ${\mu}$SR, magnetotransport, and pressure techniques, we identify a nodal superconducting state with low superfluid density at ambient pressure, with no spontaneous magnetic order detected below $T^{*}$ [1]. This indicates that the AHE originates from the band structure rather than magnetism. Under pressures up to 2 GPa, the superfluid density rises markedly in correlation with the superconducting transition temperature, the nodal pairing shifts to a nodeless state, and the CDW onset is reduced by half. Notably, AHE is fully suppressed and magnetoresistance drops by 50${\%}$ within just 0.2 GPa, highlighting the fragility of the hidden order. These results reveal an unconventional superconducting pairing in 6R-TaS$_{2}$, competing with both CDW and hidden orders. With a multifaceted approach, we establish a comprehensive phase diagram that reveals the intricate interplay and competition between the intertwined quantum orders in 6R-TaS$_{2}$.
[1] V. Sazgari et. al. and Z. Guguchia, arXiv:2503.13944 (2025).
| zurab.guguchia@psi.ch | |
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