Daily Overview: Dear readers, welcome to today’s quick overview of papers in the field of nickel-based superconductivity. The highlights of today focus on the complex interplay between superconductivity and magnetism in infinite-layer nickelate systems, as well as studies on bosonic phase transitions. In [1], the researchers observed magnetic-field-induced superconducting reentrance in Eu-doped infinite-layer nickelates, revealing the critical role of the competing magnetic responses between Eu²⁺ and Nd³⁺ rare-earth ions in regulating the superconducting state, thereby providing new perspectives on unconventional pairing mechanisms. In [2], by nano-patterning to modulate the Cooper pair phase coherence in infinite-layer samarium nickelates, h/2e magnetoresistance oscillations were directly observed experimentally, confirming the existence of 2e Cooper pairing. Additionally, two anomalous metallic phases were identified, establishing nickelates as an important platform for studying bosonic phase transitions. arXiv submission processing window: 2026-01-27 11:01 to 2026-01-27 11:34 UTC.

1. Paramagnetically driven superconducting re-entrance in Eu-doped infinite layer nickelates

  • Relevance Score: 5.1126
  • Authors: Lucia Varbaro, Lukas Korosec, Chih-Ying Hsu, Duncan T. L. Alexander, Pau Torruella, Clémentine Thibault, Benjamin A. Piot, David Le Boeuf, Javier Herrero Martin, Weibin Li, Evgenios Stylianidis, Marta Gibert, Marc Gabay, Jean-Marc Triscone
  • Link: http://arxiv.org/abs/2601.19473v1

Summary: This study investigates the magnetic-field-induced reentrant superconductivity in Eu-doped infinite-layer nickelate NdNiO₂. Through transport measurements, anomalous Hall effect analysis, and critical field modeling, it is revealed that the reentrant superconductivity originates from the delicate balance of competing effects between two magnetic rare-earth ions, Eu²⁺ and Nd³⁺. In zero magnetic field, the sample is superconducting, while the application of a weak field suppresses superconductivity due to polarization of the rare-earth ions; however, superconductivity reemerges at higher fields. This nonmonotonic behavior is associated with the Jaccarino-Peter effect, but differs from the classical case in that the mechanism involves opposite magnetic responses and compensation between the two ions. The study further shows that this phenomenon occurs only in samples with a lower critical temperature (Tc), where the temperature is sufficiently low to induce a strong paramagnetic response from the rare-earth ions. Anomalous Hall effect measurements indicate that these ions affect magnetotransport only when polarized by the magnetic field. These findings elucidate the unique role of magnetic rare-earth ions in infinite-layer nickelate superconductivity and provide new insights into the superconducting pairing mechanism.

2. Bosonic phases across the superconductor-insulator transition in infinite-layer samarium nickelate

  • Relevance Score: 4.9191
  • Authors: Menghan Liao, Heng Wang, Mingwei Yang, Chuanwu Cao, Jiayin Tang, Wenjing Xu, Xianfeng Wu, Guangdi Zhou, Haoliang Huang, Kaiwei Chen, Yuying Zhu, Peng Deng, Jianhao Chen, Zhuoyu Chen, Danfeng Li, Kai Chang, Qi-Kun Xue
  • Affiliations: Hefei National Laboratory, Southern University of Science and Technology, Peking University, University of Chinese Academy of Sciences, Tsinghua University, City University of Hong Kong, Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area, Chinese Academy of Sciences, Beijing Academy of Quantum Information Sciences
  • Link: http://arxiv.org/abs/2601.19497v3
  • Paper page: Bosonic phases across the superconductor-insulator transition in infinite-layer samarium nickelate

Summary: This study achieved a superconductor-insulator transition by fabricating spatially periodic nanonetwork patterns on infinite-layer samarium nickelate superconducting thin films, thereby modulating the phase coherence of Cooper pairs. The magnetoresistance oscillation period observed in experiments was h/2e, directly confirming the existence of 2e Cooper pairing in nickelates. The phase transition was primarily driven by enhanced superconducting fluctuations, with Cooper pairs participating in charge transport during the transition. Notably, two anomalous metallic phases were identified: one emerging under a finite magnetic field, and the other appearing in the intermediate state of the superconductor-insulator transition at zero magnetic field. Both anomalous metallic phases can be characterized by bosonic excitations, implying a dynamic role of vortices in the ground state. This work establishes nickelates as an important platform for studying bosonic phases via the modulation of Cooper pair phase coherence.