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arXiv · 0909.0373

Electrically controlled superconducting states at the heterointerface SrTiO$_3$/LaAlO$_3$

Keiji Yada·Seiichiro Onari·Yukio Tanaka·Jun-ichiro Inoue
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Abstract

We study the symmetry of Cooper pair in a two-dimensional Hubbard model with the Rashba-type spin-orbit interaction as a minimal model of electron gas generated at a heterointerface of SrTiO$_3$/LaAlO$_3$. Solving the Eliashberg equation based on the third-order perturbation theory, we find that the gap function consists of the mixing of the spin-singlet $d_{xy}$-wave component and the spin-triplet $(p_x\pm ip_y)$-wave one due to the broken inversion symmetry originating from the Rashba-type spin-orbit interaction. The ratio of the d-wave and the p-wave component continuously changes with the carrier concentration. We propose that the pairing symmetry is controlled by tuning the gate voltage.

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Keiji Yada, Seiichiro Onari, Yukio Tanaka, Jun-ichiro Inoue. 2009-10-26. Electrically controlled superconducting states at the heterointerface SrTiO$_3$/LaAlO$_3$. https://doi.org/10.1103/physrevb.80.140509

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