Thermal versus electric response of superconducting topological materials; are Majorana states more widespread than expected?

SPICE Workshop on Quantum Matter for Quantum Technologies, May 21st - May 23rd 2024

Ewelina Hankiewicz

In this talk, we will discuss different Josephson junctions based on semimetals, metals and topological insulators proximitized with s-wave superconductors. We show that thermal response can be more sensitive to Majorana bound states than an electrical
response [1,2,3]. Moreover, due to the 4pi periodicity of topological Josephson junctions, the thermal engines built on them are more efficient as the ones on the classical Josephson junctions [4].
Furthermore, we predict that the s-wave superconductivity proximitized j=3/2 particles in 2D Luttinger materials are able to host Majorana bound states even in the absence of BIA and Rashba spin-orbit couplings [5]. This originates from the hybridization of the light and heavy hole bands of the j=3/2 states in combination with the superconducting pairing. We predict that Majorana bound states should be seen in many classes of
materials like p-doped GaAs, bulk HgTe, as well as many half-Heusler compounds [5].
[1] B. Sothmann, E. M. Hankiewicz Phys. Rev. B 94, 081407 (2016).
[2] A. G. Bauer, B. Scharf, L. W. Molenkamp, E. M. Hankiewicz, and B. Sothmann
Phys. Rev. B 104, L201410 (2021).
[3] R. L. Klees, D. Gresta, J. Sturm, L. W. Molenkamp, and E. M. Hankiewicz
arXiv:2306.17845.
[4] B. Scharf, A. Braggio, E. Strambini, F. Giazotto, E. M. Hankiewicz,Communications
Physics 3, 198 (2020).
[5] J.-B. Mayer, M. A. Sierra, and E. M. Hankiewicz, Phys. Rev. B 105, 224513 (2022).