Observation of triplet superconductivity in CoSi${}_2$/TiSi${}_2$ heterostructures

Abstract

Unconventional superconductivity and in particular triplet superconductivity have been front and center of topological materials and quantum technology research. Here we report our observation of triplet superconductivity in nonmagnetic CoSi${}_2$/TiSi${}_2$ heterostructures on silicon. CoSi${}_2$ undergoes a sharp superconducting transition at a critical temperature $T_c\approx$ 1.5 K, while TiSi${}_2$ is a normal metal. We investigate conductance spectra of both two-terminal CoSi${}_2$/TiSi${}_2$ tunnel junctions and three-terminal T-shaped CoSi${}_2$/TiSi${}_2$ superconducting proximity structures. We report an unexpectedly large spin-orbit coupling in CoSi${}_2$ heterostructures. Below $T_c$, we observe (1) a narrow zero-bias conductance peak on top of a broad hump, accompanied by two symmetric side dips in the tunnel junctions, (2) a narrow zero-bias conductance peak in T-shaped structures, and (3) hysteresis in the junction magnetoresistance. These three independent and complementary observations are indicative of chiral $p$-wave pairing in CoSi${}_2$/TiSi${}_2$ heterostructures. This chiral triplet superconductivity and the excellent fabrication compatibility of CoSi${}_2$ and TiSi${}_2$ with present-day silicon integrated-circuit technology facilitate full scalability for potential use in quantum-computing devices.

38 page (main text: 17 pages, supplementary information: 21 pages)

References in corpus (29)

• Topological insulators and superconductors
• Signatures of Majorana fermions in hybrid superconductor-semiconductor nanowire devices
• Paired states of fermions in two dimensions with breaking of parity and time-reversal symmetries, and the fractional quantum Hall effect
• New directions in the pursuit of Majorana fermions in solid state systems
• Topological superconductors: a review
• Topological Superconductivity in CuxBi2Se3
• Symmetry and Topology in Superconductors - Odd-frequency pairing and edge states -
• Evidence of topological superconductivity in planar Josephson junctions
• Pronounced drop of ${}^{17}$O NMR Knight shift in superconducting state of Sr${}_2$RuO${}_4$
• Chiral Superconductors
• Quasiparticle States near the Surface and the Domain Wall in a p_x\pm i p_y-Wave Superconductor
• Edge modes, edge currents, and gauge invariance in $p_x+i{p}_y$ superfluids and superconductors
• Observation of superconductivity in 3D Dirac semimetal Cd3As2 crystal
• Unconventional Superconductivity
• Probing multiband superconductivity by point-contact spectroscopy
• Odd-frequency superconductivity
• Odd-Parity Pairing and Topological Superconductivity in a Strongly Spin-Orbit Coupled Semiconductor
• Spin-triplet superconductivity in Sr${}_2$RuO${}_4$ probed by Andreev reflection
• Anomalous charge transport in mesoscopic triplet superconductor junctions
• Theory of tunneling spectroscopy in superconducting Sr2RuO4
• Theory of enhanced proximity effect by mid gap Andreev resonant state in diffusive normal metal / triplet superconductor junctions
• Theory of tunneling conductance for normal metal/insulator/triplet superconductor junctions
• Conductance Spectroscopy of Spin-triplet Superconductors
• Theory of magnetotunneling spectroscopy in spin triplet p-wave superconductors
• Influence of the domain walls on the Josephson effect in Sr${}_2$RuO${}_4$
• Subgap current in superconducting tunnel junctions with diffusive electrodes
• Tunneling spectroscopy of topological superconductors
• Ultralow 1/f Noise in a Heterostructure of Superconducting Epitaxial Cobalt-Disilicide Thin Film on Silicon
• Observation of Anomalous Magnetic Moments in Superconducting Bi/Ni Bilayer

Cited by in corpus (21)

• Theory of Majorana zero modes in unconventional superconductors
• Josephson effect and odd-frequency pairing in superconducting junctions with unconventional magnets
• Suppressing Andreev bound state zero bias peaks using a strongly dissipative lead
• Effects of spin orbit coupling in superconducting proximity devices -- application to $\mathrm{CoS}{\mathrm{i}}_2/TiS{\mathrm{i}}_2$ heterostructures
• Controllable odd-frequency Cooper pairs in multi-superconductor Josephson junctions
• Theory of proximity effect in $s+p$-wave superconductor junctions
• Odd-frequency superconducting pairing due to multiple Majorana edge modes in driven topological superconductors
• First-principles studies of Schottky barriers and tunneling properties at Al(111)/Si(111) and CoSi${}_2$(111)/Si(111) interfaces
• Electronic conduction and superconducting properties of CoSi${}_2$ films on silicon--an unconventional superconductor with technological potential
• Anisotropic paramagnetic response of topological Majorana surface states in the superconductor ${\text{UTe}}_2$
• Proximity effect of time-reversal symmetry broken non-centrosymmetric superconductors
• Identifying Majorana bound states at quantum spin Hall edges using a metallic probe
• Spin conductance in SNN junctions with non-centrosymmetric superconductors
• Anomalous proximity effect under Andreev and Majorana bound states
• Effects of spin orbit coupling on proximity induced superconductivity
• Odd-frequency pairs and anomalous proximity effect in nematic and chiral states of superconducting topological insulators
• Magnetoresistance hysteresis in the superconduting state of Kagome CsV${}_3$Sb${}_5$
• Anisotropic differential conductance of a mixed parity superconductor/ferromagnet structure
• Current-induced magnetoresistance hysteresis in the kagome superconductor CsV${}_3$Sb${}_5$
• Critical behavior of the specific heat in Ti-Si amorphous alloys at the metal-insulator transition
• Broken time-reversal symmetry detected by tunneling spectroscopy of superconducting Pd-doped CaAgP