Extended Majorana zero modes in a topological superconducting-normal T-junction

TL;DR

This paper explores the properties of spatially extended Majorana zero modes in a topological superconducting-normal T-junction, revealing their distribution, tunability, and experimental detectability, advancing understanding of Majorana physics.

Contribution

It demonstrates that Majorana zero modes in a T-junction are spatially extended in the normal region and can be manipulated via phase tuning, providing new insights into their nature.

Findings

Majorana zero modes are spatially extended in the normal metal region.

Tuning superconducting phases can transfer the zero mode between junction arms.

Tunneling conductance calculations suggest experimental detectability.

Abstract

We investigate the sub gap properties of a three terminal Josephson T-junction composed of topologically superconducting wires connected by a normal metal region. This system naturally hosts zero energy Andreev bound states which are of self-conjugate Majorana nature and we show that they are, in contrast to ordinary Majorana zero modes, spatially extended in the normal metal region. If the T-junction respects time-reversal symmetry, we show that a zero mode is distributed only in two out of three arms in the junction and tuning the superconducting phases allows for transfer of the mode between the junction arms. We further provide tunneling conductance calculations showing that these features can be detected in experiments. Our findings suggest an experimental platform for studying the nature of spatially extended Majorana zero modes.