The Wang Jian research group of the School of Physics and collaborators observed the parallel field quantum Griffith singularity in a two-dimensional crystalline superconductor

Professor Wang Jian’s research group and collaborators from the Center for Quantum Materials Science, School of Physics, Peking University have recently observed quantum Griffiths under a parallel magnetic field in a high-quality crystalline palladium ditelluride (PdTe ₂ ) superconducting film grown by molecular beam epitaxy.

The superconductor-insulator/metal phase transition is a classic example of quantum phase transition, and it has been researched for more than 30 years

Recently, Professor Wang Jian’s research group and academician Xie Xincheng, researcher Lin Xi, and associate researcher Liu Yi of Renmin University of China, researcher Liu Haiwen of Beijing Normal University, academician Xue Qikun and associate researcher Wang Lili of Tsinghua University, and associate professor Xing Ying of China University of Petroleum (Beijing) In cooperation with others, the quantum Griffith singularity under a parallel magnetic field was observed in the high-quality crystalline palladium ditelluride (PdTe ₂ ) superconducting film grown by molecular beam epitaxy

Studies have shown that PdTe ₂ superconducting film is a second-type Ising superconductor with strong spin-orbit coupling [ Nano Lett.

In addition, the joint research team also carefully considered the influence of irrelevant parameters on the scaling theory, and proposed a direct activation scaling analysis method with an irrelevant correction term (the so-called irrelevant correction term refers to the study of the occurrence of absolute zero at a limited temperature).

The vertical magnetic field as an effective means to regulate the quantum phase transition of two-dimensional superconductors (especially two-dimensional crystalline superconductors) has been widely recognized and concerned by the international academic community

Liu Yi and Qi Shichao, a 2020 PhD student at the Center for Quantum Materials Science, School of Physics, Peking University, are the co-first authors, and Wang Jian and Liu Haiwen are the co-corresponding authors

( A) Standard four-level method to measure the electrical transport properties of PdTe ₂ thin films under a parallel magnetic field ; (b) The dependence of resistance at different temperatures under a parallel magnetic field on the magnetic field; (c) Quantum Griffith singularity under a parallel magnetic field The main experimental evidence of, namely the divergence behavior of the critical exponent; (d) The result of direct activation scale analysis with irrelevant correction terms, which gives direct evidence of the singularity of quantum Griffith

Quantum Griffith Singularity under Parallel Magnetic Field