Selective-area-grown PbTe-In hybrid nanowire and its application on pursuing topological quantum computing
ORAL
Abstract
The pursuit of topological quantum computing has driven extensive research on semiconductor-superconductor hybrid nanowires. While significant progress has been made, it has also highlighted critical challenges. Advanced transport measurements are now being employed to distinguish genuine topological signatures from trivial explanations. Concurrently, it has been recognized that the ultimate success of this platform hinges on fundamental material development: the realization of high-quality semiconductor nanowires, clean semiconductor-superconductor interfaces, as well as scalable devices.
Despite this need, the explored material candidates remain remarkably limited, predominantly featuring indium arsenide (InAs) or indium antimony (InSb) with aluminum (Al). Recent years have witnessed a growing interest in lead telluride (PbTe) with superconducting lead (Pb). These established combinations, though promising, face limitations such as small induced superconducting gaps and reduced Landé g-factors, which constrain topological protection.
In this work, we introduce a novel material system to address these challenges: epitaxial indium (In) films grown on selective-area-grown PbTe nanowires. High-resolution structural characterization confirms the formation of a continuous In film with an atomically sharp interface to the PbTe. Tunneling spectroscopy performed on these devices reveals a hard superconducting gap. Strikingly, the magnitude of this gap is approximately twice that of bulk indium, possibly due to the presence of PbTe. A similar enhancement is also observed in the critical temperature of In on a PbTe substrate.
Furthermore, we probe the hybrid system's electronic properties under external magnetic fields. The analysis of emerging subgap states yields an effective Landé g-factor that is significantly enhanced compared to bare PbTe nanowires. This contrasts with the g-factor suppression typically observed in Al-based hybrids. Finally, Josephson devices fabricated from these heterostructures exhibit clear, gate-tunable supercurrents.
Our findings establish the PbTe-In hybrid as a highly promising platform. It uniquely enhances the desirable properties of both constituents—boosting the superconductivity of In and the g-factor of PbTe. This mutual enhancement creates a favorable environment for engineering exotic phases of matter such as topological superconductivity.
References:
[1] H. Zhang et al., Nat Commun 10, 5128 (2019)
[2] Y. Jiang et al., Phys. Rev. Mater. 6, 3, 034205-034213 (2022)
[3] Z. Geng et al., Phys. Rev. Mater. 9, 084802 (2025)
Despite this need, the explored material candidates remain remarkably limited, predominantly featuring indium arsenide (InAs) or indium antimony (InSb) with aluminum (Al). Recent years have witnessed a growing interest in lead telluride (PbTe) with superconducting lead (Pb). These established combinations, though promising, face limitations such as small induced superconducting gaps and reduced Landé g-factors, which constrain topological protection.
In this work, we introduce a novel material system to address these challenges: epitaxial indium (In) films grown on selective-area-grown PbTe nanowires. High-resolution structural characterization confirms the formation of a continuous In film with an atomically sharp interface to the PbTe. Tunneling spectroscopy performed on these devices reveals a hard superconducting gap. Strikingly, the magnitude of this gap is approximately twice that of bulk indium, possibly due to the presence of PbTe. A similar enhancement is also observed in the critical temperature of In on a PbTe substrate.
Furthermore, we probe the hybrid system's electronic properties under external magnetic fields. The analysis of emerging subgap states yields an effective Landé g-factor that is significantly enhanced compared to bare PbTe nanowires. This contrasts with the g-factor suppression typically observed in Al-based hybrids. Finally, Josephson devices fabricated from these heterostructures exhibit clear, gate-tunable supercurrents.
Our findings establish the PbTe-In hybrid as a highly promising platform. It uniquely enhances the desirable properties of both constituents—boosting the superconductivity of In and the g-factor of PbTe. This mutual enhancement creates a favorable environment for engineering exotic phases of matter such as topological superconductivity.
References:
[1] H. Zhang et al., Nat Commun 10, 5128 (2019)
[2] Y. Jiang et al., Phys. Rev. Mater. 6, 3, 034205-034213 (2022)
[3] Z. Geng et al., Phys. Rev. Mater. 9, 084802 (2025)
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Publication: Zuhan Geng, Fangting Chen, Yichun Gao, Lining Yang et al., Enhanced superconductivity in PbTe-In hybrids., Phys. Rev. Mater. 9, 084802 (2025)
Presenters
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Lining Yang
- Tsinghua University
- Department of Physics, Tsinghua University