Abstract
In this letter, we report our observation of an extraordinarily rich phase diagram of a LaScO3/SrTiO3 heterostructure. Close to the superconducting transition temperature, the system hosts a superconducting critical point of the Infinite-randomness type characterized by an effective dynamical exponent ν z that diverges logarithmically. At lower temperatures, we find the emergence of a magnetic field-tuned metallic phase that co-exists with a quantum Griffiths phase (QGP). Our study reveals a previously unobserved phenomenon in 2D superconductors—an unanticipated suppression of the QGP below a crossover temperature in this system. This concealment is accompanied by the destruction of the superconducting quantum critical point (QCP) signaled by a power-law divergence (in temperature) of the effective dynamical exponent. These observations are entirely at odds with the predictions of the infinite-randomness scenario and challenge the very concept of a vanishing energy scale associated with a QCP. We develop and discuss possible scenarios like smearing of the phase transition that could plausibly explain our observations. Our findings challenge the notion that QGP is the ultimate ground state in two-dimensional superconductors.
Recommended Citation
S. Kaur et al., "Novel Emergent Phases in a Two-Dimensional Superconductor," New Journal of Physics, vol. 26, no. 8, article no. 083001, IOP Publishing, Aug 2024.
The definitive version is available at https://doi.org/10.1088/1367-2630/ad6800
Department(s)
Physics
Publication Status
Open Access
Keywords and Phrases
anomalous metal; Griffiths singularity; Oxide heterostructure; superconductor
International Standard Serial Number (ISSN)
1367-2630
Document Type
Article - Journal
Document Version
Final Version
File Type
text
Language(s)
English
Rights
© 2024 The Authors, All rights reserved.
Creative Commons Licensing
This work is licensed under a Creative Commons Attribution 4.0 License.
Publication Date
01 Aug 2024
Comments
WITH Foundation, Grant HRR/2015/000017