Quantum Griffiths Singularity in a Three-Dimensional Superconductor to Anderson Critical Insulator Transition
Disorder is ubiquitous in real materials and can have dramatic effects on quantum phase transitions. Originating from the disorder enhanced quantum fluctuation, quantum Griffiths singularity (QGS) has been revealed as a universal phenomenon in quantum criticality of low-dimensional superconductors. However, due to the weak fluctuation effect, QGS is very challenging to detect experimentally in three-dimensional (3D) superconducting systems. Here we report the discovery of QGS associated with the quantum phase transition from 3D superconductor to Anderson critical insulator in a spinel oxide MgTi_{2}O_{4} (MTO). Under both perpendicular and parallel magnetic field, the dynamical critical exponent diverges when approaching the quantum critical point, demonstrating the existence of 3D QGS. Among 3D superconductors, MTO shows a relatively strong fluctuation effect featured as a wide superconducting transition region. The enhanced fluctuation, which may arise from the mobility edge of Anderson localization, finally leads to the occurrence of 3D quantum phase transition and QGS. Our findings offer a new perspective to understand quantum phase transitions in strongly disordered 3D systems.
Authors
- Jingchao Fang (ORCID: https://orcid.org/0000-0002-9412-4244)
- Haiwen Liu (ORCID: https://orcid.org/0000-0002-0007-3117)
- Rao Li
- Shi‐Chao Qi (ORCID: https://orcid.org/0000-0002-9609-7710)
- Fucong Chen
- Kui Jin (ORCID: https://orcid.org/0000-0003-2208-8501)
- Qian Li (ORCID: https://orcid.org/0000-0001-7661-6635)
- Jian Wang (ORCID: https://orcid.org/0000-0002-7212-0904)
- Fa Wang (ORCID: https://orcid.org/0000-0002-6220-5349)
- Yi Liu (ORCID: https://orcid.org/0009-0006-9055-3718)
- Haoran Ji (ORCID: https://orcid.org/0000-0003-3541-453X)
- Ziqiao Wang (ORCID: https://orcid.org/0000-0002-1301-8731)
- Xiaoming Xie (ORCID: https://orcid.org/0000-0002-6107-2900)
- Yanan Li (ORCID: https://orcid.org/0000-0001-5999-0430)
Institutions
- Chinese Academy of Sciences (CN)
- Peking University (CN)
- Fudan University (CN)
- Beijing Normal University (CN)
- Hefei University (CN)
- Songshan Lake Materials Laboratory (CN)
- FZU ‒ Institute of Physics of the Academy of Sciences of the Czech Republic (CZ)
- Collaborative Innovation Center of Quantum Matter (CN)
- University of Chinese Academy of Sciences (CN)
- Renmin University of China (CN)
Publication Details
- Journal
- Physical Review Letters
- Published
- 2024-11-26
- DOI
- https://doi.org/10.1103/physrevlett.133.226001
- Citations
- 2
- Primary Topic
- Physics of Superconductivity and Magnetism
- Type
- article
- Field-Weighted Citation Impact
- 0.62
Funders
- National Natural Science Foundation of China
- National Key Research and Development Program of China
- Fundamental Research Funds for the Central Universities