Majorana Zero Modes in 1D Quantum Wires Without Long-Ranged Superconducting Order

TL;DR

This paper demonstrates that Majorana zero modes can exist in 1D quantum wires without the need for long-range superconducting order, broadening the conditions under which they can be realized.

Contribution

It introduces a model showing Majorana zero modes in systems with algebraically-decaying superconducting fluctuations, not requiring long-range order.

Findings

Majorana zero modes can exist without long-range superconductivity.

Bosonization confirms the stability of Majorana modes in the model.

Implications for experiments on nanowires and oxide interfaces.

Abstract

We show that long-ranged superconducting order is not necessary to guarantee the existence of Majorana fermion zero modes at the ends of a quantum wire. We formulate a concrete model which applies, for instance, to a semiconducting quantum wire with strong spin-orbit coupling and Zeeman splitting coupled to a wire with algebraically-decaying superconducting fluctuations. We solve this model by bosonization and show that it supports Majorana fermion zero modes. We argue that a large class of models will also show the same phenomenon. We discuss the implications for experiments on spin-orbit coupled nanowires coated with superconducting film and for LaAlO3/SrTiO3 interfaces.