Epitaxial Growth of Topological Superconductor β-Bi₂Pd by MBE and Magnetron Sputtering

β-Bi₂Pd exhibits hallmarks of unconventional superconductivity, pointing to spin-triplet odd-parity pairing and a potential chiral pairing state evidenced from phase-sensitive Little-Parks experiments [1-3]. Epitaxial thin films of β-Bi₂Pd generally exhibit an island growth mode [4,5]. Thicker films tend to form disconnected domains and lose global conductivity, hindering transport studies and device integration. We present a comprehensive investigation of β-Bi₂Pd thin-film growth using both molecular beam epitaxy (MBE) and DC magnetron co-sputtering. Systematic tuning of the Bi/Pd flux ratio, substrate temperature, and deposition rate reveals their decisive roles in phase formation and film morphology. A practical growth window for obtaining continuous, epitaxial, and superconducting β-Bi₂Pd films is established, paving the way for scalable quantum-device applications based on this topological superconductor.

1. X. Xu et al., Phys. Rev. Lett. 132, 056001 (2024).

2. Y. Li et al., Science 366, 238 (2019).

3. X. Xu et al., arXiv:2509.18781 (2025).

4. Y.-F. Lv et al., Sci. Bull. 62, 852 (2017).

5. Y. Lyu et al., Appl. Phys. Lett. 125, 113101 (2024).