The activated scaling behavior of quantum Griffiths singularity in two-dimensional superconductors

TL;DR

This paper demonstrates that the direct activated scaling analysis, including irrelevant corrections, effectively reveals quantum Griffiths singularity in various two-dimensional superconductors, providing a more precise method than previous finite size scaling approaches.

Contribution

It introduces and validates the application of direct activated scaling analysis with irrelevant correction to diverse 2D superconductors, enhancing the understanding of quantum Griffiths singularity.

Findings

Confirmed quantum Griffiths singularity in multiple 2D superconductors.

Showed the effectiveness of the direct activated scaling analysis with corrections.

Provided more accurate resistance data at ultralow temperatures.

Abstract

Quantum Griffiths singularity is characterized by the divergence of the dynamical critical exponent with the activated scaling law and has been widely observed in various two-dimensional superconductors. Recently, the direct activated scaling analysis with the irrelevant correction has been proposed and successfully used to analyze the experimental data of crystalline PdTe2 and polycrystalline \b{eta}-W films, which provides new evidence of quantum Griffiths singularity. Here we show that the direct activated scaling analysis is applicable to the experimental data in different superconducting films, including tri-layer Ga films and LaAlO3/SrTiO3 interface superconductor. When taking the irrelevant correction into account, we calculate the corrected sheet resistance at ultralow temperatures. The scaling behavior of the corrected resistance in a comparably large temperature regime and the theoretical fitting of the phase boundary give unambiguous evidence of quantum Griffiths singularity. Compared to the previous method based on the finite size scaling, the direct activated scaling analysis represents a more direct and precise way to analyze the experimental data of quantum Griffiths singularity in diverse two-dimensional superconductors.