Detecting Thermodynamic Phase Transition via Explainable Machine Learning of Photoemission Spectroscopy

Abstract

Identifying thermodynamic signatures of electronic phases, such as superconductivity, is challenging in low-dimensional materials due to strong fluctuations and low probing volume. Spectroscopic methods are often used to identify new bulk phases, but their main measurable quantity -- electronic energy gaps -- is no longer an effective order parameter in low-dimensional and fluctuating systems. Combining angle-resolved photoemission with a domain-adversarial neural network, we report a data-driven method to identify thermodynamic phase transitions solely based on single-particle spectra. We demonstrate 97.6$\%$ accuracy in cuprate superconductor Bi${}_2$Sr${}_2$CaCu${}_2$O${}_{8+\delta }$ with strong superconducting fluctuations. This model notably compensates for the scarcity of experimental data by leveraging virtually inexhaustible simulated data. Further, its explainability reveals the crucial role of in-gap spectral weight in detecting phase fluctuations and thermodynamic transitions. Our work pinpoints the spectroscopic signatures of fluctuating orders and enables using spectroscopy for machine-learning-assisted material discovery for low-dimensional and strong coupling systems.

10 pages, 6 figures

References in corpus (17)

• Adam: A Method for Stochastic Optimization
• Angle-resolved photoemission spectroscopy of the cuprate superconductors
• Deep Learning using Rectified Linear Units (ReLU)
• Superconductivity in single-layer films of FeSe with a transition temperature above 100 K
• Interfacial mode coupling as the origin of the enhancement of Tc in FeSe films on SrTiO3
• Electronic structure of quantum materials studied by angle-resolved photoemission spectroscopy
• Localization of preformed Cooper-pairs in disordered superconductors
• Disorder-Induced Inhomogeneities of the Superconducting State Close to the Superconductor-Insulator Transition
• Interface induced high temperature superconductivity in single unit-cell FeSe films on SrTiO3(110)
• Rapid change of superconductivity and electron-phonon coupling through 19% doping in Bi2212
• Time- and Angle-Resolved Photoemission Studies of Quantum Materials
• Point nodes persisting far beyond Tc in Bi2212
• A strongly inhomogeneous superfluid in an iron-based superconductor
• Collapse of superconductivity in cuprates via ultrafast quenching of phase coherence
• Spectroscopic Evidence of Superconductivity Pairing at 83 K in Single-Layer FeSe/SrTiO3 Films
• Role of electron-phonon coupling in excitonic insulator candidate Ta2NiSe5
• Spectroscopic evidence of high temperature superconductivity in VSe2