Superconducting ground state of the topological superconducting candidates <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi mathvariant="normal">Ti</mml:mi><mml:mn>3</mml:mn></mml:msub><mml:mi>X</mml:mi></mml:mrow></mml:math> (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>X</mml:mi><mml:mo>=</mml:mo><mml:mi>Ir</mml:mi><mml:mo>,</mml:mo><mml:mi>Sb</mml:mi></mml:math>)
Manasi Mandal, K. P. Sajilesh, Rajeswari Roy Chowdhury, D. Singh, Pabitra Kumar Biswas⃰, A. D. Hillier, R. P. Singh
Abstract
The topologically nontrivial band structure of A15 compounds has drawn a significant amount of attention owing to the possible realization of topological superconductivity. The superconducting ground state of the A15 alloys ${\mathrm{Ti}}_{3}X$ ($X=\mathrm{Ir},\mathrm{Sb}$), by muon spectroscopy, has been investigated. Zero-field muon spin relaxation measurements have shown that time-reversal symmetry is preserved in these materials. Furthermore, specific-heat and transverse-field muon rotation measurements rule out any possibility of a nodal or anisotropic superconducting gap but reveal a conventional isotropic $s$-wave gap structure. This supports the idea that these A15 superconductors are time-reversal-symmetry-preserved topological superconducting candidate compounds.