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)

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Cited by in corpus (21)

• Theory of Majorana zero modes in unconventional superconductors
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• 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