Nodeless superconductivity in the topological nodal-line semimetal CaSb2

Abstract

CaSb2 is a topological nodal-line semimetal that becomes superconducting below 1.6 K, providing an ideal platform to investigate the interplay between topologically nontrivial electronic bands and superconductivity. In this work, we investigated the superconducting order parameter of CaSb2 by measuring its magnetic penetration depth change Δλ(T) down to 0.07 K, using a tunneling diode oscillator (TDO) based technique. Well inside the superconducting state, Δλ(T) shows an exponential activated behavior, and provides direct evidence for a nodeless superconducting gap. By analyzing the temperature dependence of the superfluid density and the electronic specific heat, we find both can be consistently described by a two-gap s-wave model, in line with the presence of multiple Fermi surfaces associated with distinct Sb sites in this compound. These results demonstrate fully-gapped superconductivity in CaSb2 and constrain the allowed pairing symmetry.

References in corpus (45)

• Topological Insulators
• Topological insulators and superconductors
• Non-Abelian Anyons and Topological Quantum Computation
• Superconducting proximity effect and Majorana fermions at the surface of a topological insulator
• Unpaired Majorana fermions in quantum wires
• Topological nodal semimetals
• Titanic Magnetoresistance in WTe2
• Topological superconductors: a review
• Observation of the chiral anomaly induced negative magneto-resistance in 3D Weyl semi-metal TaAs
• Extremely large magnetoresistance and ultrahigh mobility in the topological Weyl semimetal NbP
• Superconductivity in CuxBi2Se3 and its implications for pairing in the undoped topological insulator
• Topological nodal line semimetals with and without spin-orbital coupling
• Superconductivity in Weyl Semimetal Candidate MoTe2
• Nodal-chain metals
• Observation of topological order in a Superconducting doped topological insulator (based on the Bi2Se3 class)
• Magnetic Penetration Depth in Unconventional Superconductors
• Topological semi-metals with line nodes and drumhead surface states
• Consequences of breaking time reversal symmetry in LaSb: a resistivity plateau and extreme magnetoresistance
• Phenomenological two-gap model for the specific heat of MgB_2
• Meissner - London state in superconductors of rectangular cross-section in perpendicular magnetic field
• Topological superconductivity in Dirac semimetals
• Topological Dirac Nodal Lines and Surface Charges in fcc Alkaline Earth Metals
• Dimensional crossover in topological matter: Evolution of the multiple Dirac point in the layered system to the flat band on the surface
• Long-range Coulomb interaction in nodal-ring semimetals
• Evidence for complex order parameter in La_{1.83}Sr_{0.17}CuO_4
• Possible topologically non-trivial superconducting order parameter in type-II Weyl semimetal T_d-MoTe_2
• Nonsymmorphic symmetry-required band crossings in topological semimetals
• Extremely large and significantly anisotropic magnetoresistance in ZrSiS single crystals
• Two-gap superconductivity in Ba_1-xK_xFe_2As_2: A complementary study of the magnetic penetration depth by \muSR and ARPES
• Field-induced resistivity plateau and unsaturated negative magnetoresistance in topological semimetal TaSb2
• Topological crystalline superconductivity and second-order topological superconductivity in nodal-loop materials
• Direct visualization of the nematic superconductivity in Cu${}_x$Bi${}_2$Se${}_3$
• Chiral Landau levels in Weyl semimetal NbAs with multiple topological carriers
• ${\mathbb{Z}}_2$-enriched symmetry indicators for topological superconductors in the 1651 magnetic space groups
• Quasi-Topological Electromagnetic Response of Line-node Semimetals
• Spin-triplet superconductivity in Weyl nodal-line semimetals
• Magnetotransport properties of the type II Weyl semimetal candidate Ta3S2
• Landau quantization in coupled Weyl points: a case study of semimetal NbP
• Superconductivity in the nonsymmorphic line-nodal compound CaSb${}_2$
• S-wave Superconductivity in the Dirac Line-nodal Material CaSb2
• Peak in the superconducting transition temperature of the nonmagnetic topological line-nodal material CaSb${}_2$ under pressure
• Superconductivity and Quantum Oscillations in Single Crystals of the Compensated Semimetal CaSb${}_2$
• Superconductivity in the nodal-line compound La${}_3$Pt${}_3$Bi${}_4$
• Quasi-2D Fermi surface of superconducting line-nodal metal CaSb${}_2$
• Fermiology of a topological line-nodal compound CaSb2 and its implication to superconductivity: angle-resolved photoemission study

Cited by in corpus (6)

• Intrinsic superconducting diode effects in tilted Weyl and Dirac semimetals
• Pressure evolution of the normal- and superconducting-state properties of the line-nodal material CaSb${}_2$ revealed by ${}^{123}$Sb nuclear quadrupole resonance
• Nodal-line semimetals and their variance
• Subtle Structural Anomaly under Compression in Line-Nodal CaSb${}_2$
• Determination of the London penetration depth with the tunnel diode oscillator technique
• Topological materials with extensive flat-band surface states