Daily Overview: Today’s highlight work focuses on the exploration of a peculiar superconducting phase-transition phenomenon in infinite-layer nickelates. A study has realized an “inverse superconducting transition” that exceeds the liquid‑helium cooling limit in Eu‑based infinite‑layer nickelates (EuₓNd₁₋ₓNiO₂ and EuₓPr₁₋ₓNiO₂). It is found that, through magnetic‑field tuning, the superconducting zero‑resistance state is confined to a specific window between a lower turnover temperature and a higher normal superconducting critical temperature, manifested by the fact that raising the temperature or increasing the current density can paradoxically drive the system from a resistive state into a superconducting state. This anomalous behavior is attributed to the temperature‑induced alternation in the relative strength of the Eu²⁺ 4f⁷‑related compensating effective field and the upper critical field, and is corroborated by the re‑emergence of superconductivity at very low temperatures. The discovery not only offers a new paradigm for constructing high‑temperature superconducting systems with tunable magnetic interactions, but also opens up fresh application prospects for exploring quantum phenomena that reverse thermal decoherence and for the inverse design of quantum‑phase‑transition devices. arXiv submission processing window: 2026-06-18 00:00 to 2026-06-18 00:00 UTC.

1. Counterintuitive inverse superconducting transition beyond 4He-cooling limit

  • Relevance Score: 4.5473
  • Authors: Haowen Han, Yi Bian, Tong Ma, Yusong Zhao, Nuofu Chen, Chuanying Xi, Ze Wang, Binghui Ge, Hongliang Dong, Jia-Cai Nie, Ho-Kwang Mao, Jikun Chen
  • Affiliations: Center for High Pressure Science and Technology Advanced Research, Anhui University, University of Science and Technology Beijing, Institute for Shanghai Advanced Research in Physical Sciences (SHARPS), Chinese Academy of Sciences, North China Electric Power University, Beijing Normal University
  • Link: https://arxiv.org/abs/2606.18683
  • Paper page: Counterintuitive inverse superconducting transition beyond 4He-cooling limit

Summary: This paper reports inverse superconducting transitions realized beyond the liquid-helium cooling limit in Eu-based infinite-layer nickelates (EuxNd1‑xNiO₂ and EuxPr1‑xNiO₂). Through magnetic-field tuning, the zero-resistance superconducting state is observed to be confined between a lower critical temperature (Tc‑inv ≈ 2.6–5.4 K) and a higher normal Tc in both overdoped and underdoped regions; raising the temperature or increasing the current density can drive the system from a resistive state into superconductivity, which then vanishes again at higher temperatures and currents. Systematic temperature-dependent transport measurements reveal that this inverse superconducting transition in the Kelvin range arises from the temperature-driven alternating dominance of a compensating effective magnetic field associated with Eu²⁺ 4f⁷ moments and the upper critical field, supported by a temperature-induced re-entrant superconductivity phenomenon where superconductivity reappears at around 300 mK under an applied magnetic field. This work establishes a high-temperature superconductor system with magnetically reconstructed interactions as a platform for exploring quantum phenomena that reverse the paradigm of thermal decoherence, and opens application avenues for the inverse design of quantum phase-transition devices.