Towards Quantum Computing Devices based on High-Tc Superconductor and Topological Insulator

by Prof. Jonghyun Song (Chungnam National University)

Tuesday 14 Jul 2026, 16:00 → 17:30 Asia/Seoul

C101 (Changjo-gwan, KAIST (Munji Campus))

High-temperature superconductors (HTSs) offer a promising platform for realizing quantum devices operating at elevated temperatures, while topological insulators (TIs) provide robust spin-momentum-locked surface states capable of hosting unconventional superconductivity through the proximity effect. In this work, we conduct foundational research toward quantum computing devices based on HTS/TI hybrid structures by developing and evaluating various Josephson junction architectures. To identify reliable junction platforms, we investigate bicrystal grain-boundary Josephson junctions and lateral Josephson junctions fabricated using advanced microfabrication techniques. Particular attention is devoted to interface engineering, Josephson transport, current-phase relations, and the influence of the d-wave pairing symmetry of HTSs on junction characteristics. These studies establish key fabrication technologies and design principles for integrating topological insulators with high-Tc superconductors. The ultimate goal is to establish high-quality HTS/TI Josephson junctions capable of inducing topological superconductivity and providing a scalable platform for fault-tolerant quantum computing based on topological qubits. The resulting framework lays the technological foundation for realizing robust high-temperature superconducting quantum devices and next generation quantum computing architectures.

260714_Jonghyun_Song.pdf