Lin Er Chow1,King yau Yip2,Mathieu Pierre3,Shengwei Zeng1,Zhaoting Zhang1,Tobias Heil4,Julia Deuschle4,Proloy Nandi1,Sujith Kunniniyil Sudheesh1,Zhi Shiuh Lim1,Zhaoyang Luo1,Marc Nardone3,A. Zitouni3,Peter Van Aken4,Michel Goiran3,Swee Kuan Goh2,Walter Escoffier3,Ariando Ariando1
National University of Singapore1,The Chinese University of Hong Kong2,Université de Toulouse3,Max Planck Institute for Solid State Research4
Lin Er Chow1,King yau Yip2,Mathieu Pierre3,Shengwei Zeng1,Zhaoting Zhang1,Tobias Heil4,Julia Deuschle4,Proloy Nandi1,Sujith Kunniniyil Sudheesh1,Zhi Shiuh Lim1,Zhaoyang Luo1,Marc Nardone3,A. Zitouni3,Peter Van Aken4,Michel Goiran3,Swee Kuan Goh2,Walter Escoffier3,Ariando Ariando1
National University of Singapore1,The Chinese University of Hong Kong2,Université de Toulouse3,Max Planck Institute for Solid State Research4
Standing beside copper in the periodic table, Ni<sup>1+</sup> state in infinite-layer phase hosts 3d<sup>9</sup> electronic structure with lifted orbital degeneracy that resembles Cu<sup>2+</sup> state in the high-<i>T</i><sub>c</sub> cuprate superconductors [1,2]. Realizing and studying superconductivity in nickelate has been one of the most strategic paths to a closer step toward the secret makeup of high-temperature superconductivity. Despite more than two decades of theoretical predictions, superconducting infinite-layer nickelate was only successfully synthesized in 2019 in the thin-film form [3]. Obstructed by challenging material synthesis and various structural defects, many critical parameters such as the upper critical fields and superconducting anisotropies for this newfound quasi-two-dimensional layered superconductor remain poorly understood. In continuation of our efforts in optimizing the stabilization of the superconducting infinite-layer phase, we successfully fabricate high crystallinity samples with virtually a monocrystalline infinite-layer phase with thickness > 10 nm, more than twice the previously achieved thickness. We perform a series of magnetotransport measurements using magnetic fields up to 55 T at a temperature down to 30 mK. In contrast to the expected trend from cuprates, we observed a strong dependence of the upper critical fields on the rare earth ion [4]. The intrinsic angular dependence of the superconducting observables will also be discussed.<br/><br/>[1] T. M. Rice, <i>Phys. Rev. B - Condens. Matter Mater. Phys. </i><b>59</b> (1999) 7901-7906<br/>[2] K. W. Lee, W. E. Pickett, <i>Phys. Rev. B - Condens. Matter Mater. Phys. </i><b>70</b> (2004) 1-7<br/>[3] D. Li <i>et. al.</i>, <i>Nature </i><b>572</b> (2019) 624-627<br/>[4] L. E. Chow <i>et. al.</i>,<i> arXiv:2204.12606 </i>(2022)<br/><br/><b>Acknowledgment:</b><br/>This research is supported by the Ministry of Education (MOE), Singapore, under its Tier-2 Academic Research Fund (AcRF), Grant No. MOET2EP50121-0018, and Research Grants Council of the Hong Kong SAR, Grant No. A-CUHK 402/19. We acknowledge the support of LNCMI-CNRS, a member of the European Magnetic Field Laboratory (EMFL) under the proposal numbers TMS10-219 and TMS10-221 and the funding support from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 823717 - ESTEEM3.