- 25.06.2019 -
NEST Seminar: E. Hankiewicz 25/06/2019

Ewelina Hankiewicz, Physics Department, Wurzburg University, Germany

**Unconventional superconductivity in topological insulators and Rashba 2DEGs**

Tuesday 25 June 2019 - 11:00

NEST seminar room 1 floor

Abstract:

A topological insulator in the proximity to an s-wave superconductor is the prefect material to detect signatures of Majorana fermions. S-wave superconductor on the top of the surface states of 3D TI generates s-wave and p-wave pairing mixture in the surface state due to the spin-momentum locking [1,2]. We predict that in the Josephson junction setup, namely superconductor (S) /surface state of topological insulator/superconductor (S), existence of this p-wave component leads to novel features in transport like superconducting Klein tunneling i.e. the perfect transmission of hybridized Majorana states for normal incidence, the non-sinusoidal current phase relation [2] and unusual phase-dependent thermal conductance [3]. Further, we propose the experimental setups to observe signatures of Majorana fermions in the ac Josephson effect on TI hybrid structures [4] and in phase controlled Josephson junctions based on Rashba 2DEGs [5,6].

[1] L. Fu and C. L. Kane, Phys. Rev. Lett. 100, 096407 (2008).

[2] G. Tkachov and E. M. Hankiewicz, Phys. Rev. B 88, 075401 (2013).

[3] B. Sothmann and E. M. Hankiewicz Phys. Rev. B 94, 081407(R) (2016); B. Sothmann, F. Giazotto, and E. M. Hankiewicz New J. Phys. 19, 023056 (2017).

[4] F. Dominguez, O. Kashuba, E. Bocquillon, J. Wiedenmann, R. S. Deacon, T. M. Klapwijk, G. Platero, L. W. Molenkamp, B. Trauzettel, and E. M. Hankiewicz Phys. Rev. B 95, 195430 (2017).

[5] H. Ren, F. Pientka, S. Hart, A. T. Pierce, M. Kosowsky, L. Lunczer, R. Schlereth, B. Scharf, E. M. Hankiewicz, L. W. Molenkamp, B. I. Halperin and A. Yacoby, Nature 569, 93(2019).

[6] B. Scharf, F. Pientka, H. Ren, A. Yacoby, and E. M. Hankiewicz Phys. Rev. B 99, 214503 (2019).

**Info** alessandro.braggio@nano.cnr.it