Speaker: Haiwen Liu

Time: 2:00pm, Jan 30th (Tuesday)

Location: X1-B4003, Jiangwan Campus

Affiliation: Department of Physics, Beijing Normal University, Beijing

Abstract:

In the first part of this talk, I will show our theoretical attempts to study the in-plane critical magnetic field of 2D Ising superconducting systems and propose a microscopic theory for these systems with or without inversion symmetry, which has treated the impurity scattering and Rashba spin orbital scattering on equal footing [1, 2]. The microscopic theory is consistent with recent experimental results in Pb [3, 4] and stanine [5] superconducting ultra-thin films and so on.

Moving on to the second part of this talk, I will introduce the fascinating Ohmic dissipation effect on the transport properties of 2D disordered superconductors. Specifically, this effect leads to the emergence of Quantum Griffiths singularity in superconductor-metal transition systems [6-8], as well as a bosonic strange metal behavior in 2D nano-patterned YBCO films near the critical resistance of superconductor-insulator transition [9], and the bosonic anomalous metallic state in 2D superconductors [10-11]. We analyze the quantum XY model in two dimensions with Ohmic dissipation and provide quantitative explanations for the relevant experimental observations andnew predictions on Nernst signal in these systems [12].

References:

1. H Ji, H. Liu*, H. Jiang, X. C. Xie*, Advances in Physics: X 6, 1884133 (2021).

2. H.C. Liu, H. Liu*, D. Zhang, X. C. Xie, Phys. Rev. B 102, 174510 (2020).

3. Y. Liu, H. Liu*, J. Wang*, X. C. Xie, et al., Physical Review X 8, 021002 (2018).

4. Y. Liu, H. Liu*, J. Wang*, X. C. Xie, et al., Nature Communications 10, 3633 (2019).

5. J. Falson, H. Liu*, D. Zhang*, et al., Science 367, 1454 (2020).

6. Y. Xing, et al, Science 350 542, (2015).

7. Y. Liu, H. Liu*, J. Wang*, X. C. Xie, et al., Phys. Rev. Lett.127, 137001 (2021).

8. C. Huang, H. Liu*, J. Wang*, et al., Science Bulletin 66,1830 (2021).

9. C. Yang, H. Liu, X. C. Xie, et al., Nature 601, 205 (2022).

10. C. Yang, et al., Science. 366, 1505 (2019).

11. Y. Li, et al., arXiv:2111.15488; D. Qiu, et al., under review.

12. H. Liu, X. C. Xie, under preparation.

About the Speaker:

Haiwen Liu received his bachelor’s degree from PKU in 2006, and his Doctoral degree from the Institute of Physics at CAS in 2012. From 2012 to 2015, he served as a postdoctoral researcher at ICQM, PKU. He currently holds a professorship in the Department of Physics at Beijing Normal University. His current research interests include the study of disorder and dissipation effects on the quantum transport properties of superconducting and topological systems