Evidence of nodal f-wave superconductivity in monolayer 1H-TaS$_2$ with hidden order fluctuations

Abstract

Unconventional superconductors represent one of the fundamental directions in modern quantum materials research. In particular, nodal superconductors are known to appear naturally in strongly correlated systems, including cuprate superconductors and heavy-fermion systems [1][2][3][4][5][6]. Van der Waals materials hosting superconducting states are well known [7-13], yet nodal monolayer van der Waals superconductors have remained elusive [14][15][16][17]. Here, we show that pristine monolayer 1H-TaS2 realizes a nodal superconducting state of f-wave spin-triplet symmetry. We show that including non-magnetic disorder drives the nodal superconducting state to a conventional gapped s-wave state. Furthermore, we observe the emergence of many-body excitations potentially associated to the unconventional pairing mechanism. Our results demonstrate the emergence of nodal superconductivity in a van der Waals monolayer, providing a building block for van der Waals heterostructures exploiting unconventional superconducting states.