Majorana ensembles with fractional entropy and conductance in nanoscopic systems

TL;DR

This paper explores how topological superconductors in nanoscopic systems exhibit fractional entropy and conductance behaviors at high temperatures, aiding experimental detection of Majorana states through thermodynamic and transport signatures.

Contribution

It demonstrates that increasing temperature leads to a robust accumulation of Majorana thermodynamic states and fractional entropy, reducing phase dependence and facilitating experimental observation.

Findings

Fractional Majorana entropy observed at high T

Conductance reaches a fractional plateau at high T

Entropy dependence on tunneling phases diminishes with temperature

Abstract

Quantum thermodynamics is a promising route to unambiguous detections of Majorana bound states. Being fundamentally different from quantum transport, this approach reveals unique Majorana thermodynamic behavior and deepens our insight into Majorana quantum transport itself. Here we demonstrate that a nanoscopic system with topological superconductors produces a remarkable accumulation of Majorana thermodynamic states in wide ranges of Majorana tunneling phases by means of increasing its temperature $T$. Revealing this physical behavior is twofold beneficial. First, it significantly reduces the dependence of the entropy on the tunneling phases which become almost irrelevant in experiments. Second, the fractional Majorana entropy $S_M^{(2)}=k_B\ln(2^\frac{3}{2})$ may be observed at high temperatures substantially facilitating experiments. Analyzing quantum transport, we predict that when the temperature increases, the above thermodynamic behavior will induce an anomalous increase of the linear conductance from vanishing values up to the unitary fractional Majorana plateau $G_M=e^2/2h$ extending to high temperatures.