|
1
|
Ning Z, Qian J, Liu Y, Chen F, Zhang M, Deng L, Yuan X, Ge Q, Jin H, Zhang G, Peng W, Qiao S, Mu G, Chen Y, Li W. Coexistence of Ferromagnetism and Superconductivity at KTaO 3 Heterointerfaces. NANO LETTERS 2024; 24:7134-7141. [PMID: 38828962 DOI: 10.1021/acs.nanolett.4c02500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2024]
Abstract
The coexistence of superconductivity and ferromagnetism is a long-standing issue in superconductivity due to the antagonistic nature of these two ordered states. Experimentally identifying and characterizing novel heterointerface superconductors that coexist with magnetism presents significant challenges. Here, we report the observation of two-dimensional long-range ferromagnetic order in a KTaO3 heterointerface superconductor, showing the coexistence of superconductivity and ferromagnetism. Remarkably, our direct current superconducting quantum interference device measurements reveal an in-plane magnetization hysteresis loop persisting above room temperature. Moreover, first-principles calculations and X-ray magnetic circular dichroism measurements provide decisive insights into the origin of the observed robust ferromagnetism, attributing it to oxygen vacancies that localize electrons in nearby Ta 5d states. Our findings suggest KTaO3 heterointerfaces as time-reversal symmetry breaking superconductors, injecting fresh momentum into the exploration of the intricate interplay between superconductivity and magnetism enhanced by the strong spin-orbit coupling inherent to the heavy Ta in 5d orbitals.
Collapse
Affiliation(s)
- Zhongfeng Ning
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - Jiahui Qian
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - Yixin Liu
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Fan Chen
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Mingzhu Zhang
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Liwei Deng
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xinli Yuan
- Thermo Fisher Scientific China, Shanghai 201203, China
| | - Qingqin Ge
- Thermo Fisher Scientific China, Shanghai 201203, China
| | - Hua Jin
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
| | - Guanqun Zhang
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - Wei Peng
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shan Qiao
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Gang Mu
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yan Chen
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - Wei Li
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| |
Collapse
|
|
2
|
Zhang G, Wang L, Wang J, Li G, Huang G, Yang G, Xue H, Ning Z, Wu Y, Xu JP, Song Y, An Z, Zheng C, Shen J, Li J, Chen Y, Li W. Spontaneous rotational symmetry breaking in KTaO 3 heterointerface superconductors. Nat Commun 2023; 14:3046. [PMID: 37236987 DOI: 10.1038/s41467-023-38759-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 05/11/2023] [Indexed: 05/28/2023] Open
Abstract
Broken symmetries play a fundamental role in superconductivity and influence many of its properties in a profound way. Understanding these symmetry breaking states is essential to elucidate the various exotic quantum behaviors in non-trivial superconductors. Here, we report an experimental observation of spontaneous rotational symmetry breaking of superconductivity at the heterointerface of amorphous (a)-YAlO3/KTaO3(111) with a superconducting transition temperature of 1.86 K. Both the magnetoresistance and superconducting critical field in an in-plane field manifest striking twofold symmetric oscillations deep inside the superconducting state, whereas the anisotropy vanishes in the normal state, demonstrating that it is an intrinsic property of the superconducting phase. We attribute this behavior to the mixed-parity superconducting state, which is an admixture of s-wave and p-wave pairing components induced by strong spin-orbit coupling inherent to inversion symmetry breaking at the heterointerface of a-YAlO3/KTaO3. Our work suggests an unconventional nature of the underlying pairing interaction in the KTaO3 heterointerface superconductors, and brings a new broad of perspective on understanding non-trivial superconducting properties at the artificial heterointerfaces.
Collapse
Affiliation(s)
- Guanqun Zhang
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai, 200433, China
| | - Lijie Wang
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai, 200433, China
| | - Jinghui Wang
- ShanghaiTech Laboratory for Topological Physics & School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Guoan Li
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Guangyi Huang
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai, 200433, China
| | - Guang Yang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Huanyi Xue
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai, 200433, China
| | - Zhongfeng Ning
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai, 200433, China
| | - Yueshen Wu
- ShanghaiTech Laboratory for Topological Physics & School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Jin-Peng Xu
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Yanru Song
- ShanghaiTech Quantum Device Lab, ShanghaiTech University, Shanghai, 201210, China.
| | - Zhenghua An
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai, 200433, China
- Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai, 200433, China
| | - Changlin Zheng
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai, 200433, China
| | - Jie Shen
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.
- Songshan Lake Materials Laboratory, Dongguan, 523808, China.
| | - Jun Li
- ShanghaiTech Laboratory for Topological Physics & School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China.
| | - Yan Chen
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai, 200433, China
| | - Wei Li
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai, 200433, China.
| |
Collapse
|