# Majorana finite frequency nonequilibrium quantum noise

## TL;DR

This paper investigates the universal finite frequency noise spectra of Majorana bound states in nonequilibrium quantum devices, revealing characteristic resonances and antiresonances relevant for quantum measurement technologies.

## Contribution

It provides a detailed analysis of the universal features of Majorana finite frequency noise spectra, including photon absorption spectra and characteristic resonances, in nonequilibrium conditions.

## Key findings

- Revealed universal Majorana plateaus and resonances in noise spectra.
- Demonstrated detailed structure of photon absorption spectra across energy scales.
- Connected theoretical results with experimental measurement capabilities.

## Abstract

Quantum finite frequency noise is one of fundamental aspects in quantum measurements performed during quantum information processing where currently Majorana bound states offer an efficient way to implement fault-tolerant quantum computation via topological protection from decoherence or unitary errors. Thus a detailed exploration of Majorana finite frequency noise spectra, preferably in a nonequilibrium device, is a timely challenge of fundamental importance. Here we present results on finite frequency differential noise that is the derivative of the noise with respect to the frequency. This quantity has universal units of $e^2$ and scans in high detail all peculiarities of the Majorana noise clearly demonstrating its universal finite frequency features. In particular, we provide photon absorption spectra on all energy scales and reveal a rich structure including universal Majorana plateaus as well as universal Majorana resonances and antiresonances at characteristic frequencies. Our results are of immediate interest to state-of-the-art experiments involving quantum noise mesoscopic detectors able to separately measure photon absorption and emission spectra.

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Source: https://tomesphere.com/paper/1904.05827