2026-06-15 アルゴンヌ国立研究所（ANL）
＜関連情報＞
- https://www.anl.gov/article/designer-superconducting-diamond-researchers-uncover-path-to-multimodality-quantum-chips
- https://www.pnas.org/doi/10.1073/pnas.2607730123
臨界ドープされた超伝導ダイヤモンド薄膜における異方性三相秩序の出現 Emergent anisotropic three-phase order in critically doped superconducting diamond films
Jyotirmay Dwivedi, Saurav Islam, Jake Morris, +9 , and Nitin Samarth
Proceedings of the National Academy of Sciences Published:May 11, 2026
DOI:https://doi.org/10.1073/pnas.2607730123
Significance
In heavily boron doped diamond (HBDD), doping induced disorder can lead to inhomogeneity in the superconducting order parameter even in structurally homogeneous samples. We probe this intrinsically granular superconducting state in single crystalline homoepitaxial HBDD films using magnetotransport. Our measurements reveal a three-phase anisotropic order in this disordered superconductor, with distinct symmetries that can be controlled by temperature, magnetic field, and current direction. Understanding the emergence of this anisotropic transport in the superconducting phase of HBDD can lead us toward higher Tc in diamond.
Abstract
Two decades since its discovery, superconducting heavily boron-doped diamond (HBDD) still poses fundamental questions that need to be answered to unlock its full potential for quantum applications. We use electrical magnetotransport measurements of critically doped homoepitaxial single crystal HBDD films to reveal signatures of intrinsically granular superconductivity. By studying the dependence of electrical resistivity on temperature and magnetic field vector, we infer that this granularity arises from doping induced disorder. We observe an unexpected three-phase anisotropy in the magnetoresistance, accompanied by a spontaneous transverse voltage (Hall anomaly). Our findings indicate the emergence of an anisotropic order in an otherwise isotropic single crystal HBDD film, offering insights into the mechanism of superconductivity in this quantum material.
