Engineering Papers⌕ Search

DOE OSTI · 2927556

A topological superconductor tuned by electronic correlations

Abstract

A topological superconductor, characterized by either a chiral order parameter or a topological surface state in proximity to bulk superconductivity, is foundational to topological quantum computing. A key open challenge is whether electron-electron interactions can tune such topological superconducting phases. Here, we provide experimental signatures of a unique topological superconducting phase in competition with electronic correlations in 10-unit-cell thick FeTe x Se 1-x films grown on SrTiO 3 substrates. When the Te content x exceeds 0.7, we observe a topological transition marked by the emergence of a superconducting surface state. Near the FeTe limit, the system undergoes another transition where the surface state disappears, and superconductivity is suppressed. Theory suggests that electron-electron interactions in the odd-parity xy− band drives this second topological transition. The flattening and eventual decoherence of d xy -derived bands track the superconducting dome, linking correlation effects directly to superconducting coherent transport. Our work establishes many-body electronic correlations as a sensitive knob for tuning topology and superconductivity, offering a pathway to engineer new topological phases in correlated materials.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Lin, Haoran [Univ. of Chicago, IL (United States)] (ORCID:0000000344311823), Jacobs, Christopher L. [West Virginia Univ., Morgantown, WV (United States)], Yan, Chenhui [Univ. of Chicago, IL (United States)] (ORCID:0000000254409536), Nolan, Gillian M. [Univ. of Illinois at Urbana-Champaign, IL (United States)] (ORCID:0000000323569075), Berruto, Gabriele [Univ. of Chicago, IL (United States)] (ORCID:0009000552178489), Singleton, Patrick [Univ. of Chicago, IL (United States)], Nguyen, Khanh Duy [Univ. of Chicago, IL (United States)] (ORCID:0000000273604564), Bai, Yunhe [Univ. of Chicago, IL (United States)] (ORCID:0000000258896415), Gao, Qiang [Univ. of Chicago, IL (United States)] (ORCID:0000000159924871), Wu, Xianxin [Chinese Academy of Sciences (CAS), Beijing (China)] (ORCID:0009000439167120), Liu, Chao-Xing [Pennsylvania State Univ., University Park, PA (United States)] (ORCID:0000000318811365), Yan, Gangbin [Univ. of Chicago, IL (United States)] (ORCID:0000000247119063), Choi, Suin [Univ. of Chicago, IL (United States)], Liu, Chong [Univ. of Chicago, IL (United States)] (ORCID:0000000348517888), Guisinger, Nathan P. [Argonne National Laboratory (ANL), Argonne, IL (United States)], Huang, Pinshane Y. [Univ. of Illinois at Urbana-Champaign, IL (United States)] (ORCID:0000000210951833), Mandal, Subhasish [West Virginia Univ., Morgantown, WV (United States)] (ORCID:0000000196624165), Yang, Shuolong [Univ. of Chicago, IL (United States)] (ORCID:0000000282009898). 2025-12-26. A topological superconductor tuned by electronic correlations. https://doi.org/10.1038/s41467-025-67957-1

Cite the original work for its findings. Save a collection to share your selection of sources.

Discover connections

Connections use source metadata and explicit phrase matches, not verified experimental comparisons.

KEEP EXPLORING

Related reports

Cyclic moisture reactivation of calcium sorbents for long duration thermochemical energy storage

The transition to a flexible and reliable energy infrastructure, using electro-thermal energy generation technologies such as geothermal, concentrated solar power, and nuclear, usually demands simultaneous advancement of thermal energy storage (TES) to support on-demand electricity generation and industrial applications while mitigating the inherent intermittency of renewable energy sources and power outages from direct energy generation. Among TES technologies, thermochemical energy storage (TCES) based on calcium looping emerges as a compelling high-power energy storage candidate due to its high reaction enthalpy, compatibility with elevated operating temperatures, and abundance of low-cost materials. However, the long-term durability of calcium-based sorbents for TCES is hindered by surface sintering and particle aggregation, leading to performance degradation over repeated thermal cycles. This study explores a moisture hydration-based strategy to regenerate a degraded calcium sorbent and mitigate performance degradation for long duration TCES. The addition of moisture transforms calcium oxide into calcium hydroxide and produces intercalation water layers, associated with a regenerated surface area and reduced calcium oxide crystallite size. Both these effects are beneficial in restoring the sorbents' reactivity for carbonization. Additionally, an optimized hydration-assisted reactivation protocol balances the recovered energy storage capacity with heating penalty required for moisture removal from hydrated samples, resulting in an enhanced energy storage capacity up to 176% compared to benchmark sorbents that undergo cycling without reactivation after 60 cycles. In conclusion, these results highlight the potential of hydration-assisted reactivation to enhance the long-term performance of TCES, providing an effective pathway to advancing electro-thermal storage technologies.

36 MATERIALS SCIENCE↗