Determination of spin polarization of metals and gap of superconductors by spin-polarized Andreev reflection spectroscopy

Zhu，Y. J.W.1,2; Chen，T. Y.1,2

2022-12-15

10.1016/j.jmmm.2022.170017

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS   Impact Factor & Quartile

0304-8853

Andreev reflection spectroscopy (ARS) is a unique technique that can determine the spin polarization of a metal as well as the gap of a superconductor but d-wave superconductors are seldomly used in ARS due to the lack of quantitative model to extract parameters from experiments. Here we calculate spin-polarized ARS based on the modified Blonder-Tinkham-Klapwijk model for both s- and d-wave superconductors of a three-dimensional (3D) interface with a point angle. We show that the 3D interface and the point angle can drastically affect the spectra for both s- and d-wave ARS. For s-wave, the 3D effect is similar to that of an interfacial barrier but it can generate a variety of rich features in d-wave ARS and induce Andreev bound states (ABS). The spin polarization can linearly suppress both s- and d-wave spectra including ABS. We show that the ABS states can be controlled by the spin polarization, the point angle and the interfacial barrier but very high polarization is required to completely suppress the ABS. Furthermore, the Fermi wavevector mismatch as well as the carrier effective mass mismatch can cause effects very similar to that of an interfacial barrier for both s- and d-wave ARS.

EI

English

First ; Corresponding

National Natural Science Foundation of China[11974158];Guangdong Science and Technology Department[2020B0303050001];Guangdong Science and Technology Department[2021B0101300001];

20224613103632

Electromagnetic wave reflection ; Shear waves ; Superconducting materials

Superconducting Materials:708.3 ; Electromagnetic Waves:711 ; Mechanics:931.1 ; High Energy Physics:932.1

PHYSICS

2-s2.0-85141528825

Scopus

1.Shenzhen Institute for Quantum Science and Engineering,Southern University of Science and Technology,Shenzhen,518055,China
2.International Quantum Academy,Shenzhen,518048,China

Zhu，Y. J.W.,Chen，T. Y.. Determination of spin polarization of metals and gap of superconductors by spin-polarized Andreev reflection spectroscopy[J]. JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS,2022,564.

Zhu，Y. J.W.,&Chen，T. Y..(2022).Determination of spin polarization of metals and gap of superconductors by spin-polarized Andreev reflection spectroscopy.JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS,564.

Zhu，Y. J.W.,et al."Determination of spin polarization of metals and gap of superconductors by spin-polarized Andreev reflection spectroscopy".JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS 564(2022).