• DOI:10.1103/PhysRevB.105.094513
• Corpus ID: 246016429

Time-reversal symmetry breaking in frustrated superconductor Re$_2$Hf

@inproceedings{Manda2022TimereversalSB,
  title={Time-reversal symmetry breaking in frustrated superconductor Re\$\_2\$Hf},
  author={Manasi Manda and A Kataria and Chandana Patra and Dharmendra Singh and Pabitra K. Biswas and Adrian D. Hillier and Tanmoy Das and R. P. Singh},
  year={2022}
}

• Manasi Manda, A. Kataria, +5 authors R. Singh
• Published 16 January 2022
• Physics

Geometrical frustration leads to novel quantum phenomena such as the spin-liquid phase in triangular and Kagomé lattices. Intra-band and inter-band Fermi surface (FS) nesting can drive unique superconducting (SC) ground states with d -wave and s ± pairing symmetries, respectively, according to the criterion that the SC gap changes sign across the nesting wavevector. For an odd number of FSs, when multiple inter-band nesting is of comparable strength, the sign-reversal criterion between different FS sheets can leads to frustration, which promotes novel SC order parameters. Here we report the experimental observation of a time-reversal symmetry breaking pairing state in Re 2 Hf resulting from FS nesting frustration. Furthermore, our electronic specific heat and transverse-field µ SR experiments suggest a fully gaped pairing symmetry. The first-principle electronic structure calculation reveals multiple Fermi surface sheets with comparable inter-band nesting strength. Implementing the ab-initio band structure, we compute spin-fluctuation mediated SC pairing symmetry which reveals a s + is (cid:48) -pairing state - consistent with experimental observations. Our investigation demonstrates a novel SC state which provides a putative setting for both applied and fundamental study.