Surface superconductor-insulator transition induced by electric field

Physical Review B: Condensed Matter and Materials Physics. 2023. Vol. 108. No. 5. Article 054508.

Yin L., Bai Y., Zhang M., A. A. Shanenko, Chen Y.

It is well known that the electric field can induce phase transitions between superconducting, metallic and

insulating states in thin-film materials due to its control of the charge carrier density. Since a similar effect on the

charge carriers can also be expected for surfaces of bulk samples, here, we investigate the transformation of the

surface states in a superconductor under an applied screened electric field. Our study is performed by numerically

solving the self-consistent Bogoliubov–de Gennes equations for the one-dimensional attractive Hubbard model.

It is found that the surface insulating regime occurs at sufficiently large (but still experimentally accessible)

electric fields. Our calculations yield the phase diagram of the surface superconducting, metallic, and insulating

states for a wide range of temperatures and applied fields. Our results are in qualitative agreement with the phase

diagram obtained with the transport measurements for (Li, Fe)OHFeSe thin flakes

[Ma et al., Sci. Bull. 64, 653 (2019); Yin et al., ACS Nano 14, 7513 (2020)]

Keywords: переход сверхпроводник-изолятор, surface superconductivity, поверхностная сверхпроводимость, Electric field control, superconductor-isolator transition, контроль электрическим полем

Publication based on the results of: Studying quantum effects in super- and semi-conducting metamaterials (2023)