# Sensing Floquet-Majorana fermions via heat transfer

## TL;DR

This paper demonstrates that heat transfer measurements can reliably detect Floquet-Majorana modes and dynamical phase transitions in a dissipative XY spin chain, providing a practical alternative to quasi-energy based detection methods.

## Contribution

It introduces a robust method using heat current derivatives and spin density Fourier analysis to identify Floquet-Majorana modes in dissipative systems, bypassing quasi-energy measurement challenges.

## Key findings

- Heat current derivative signals topological phase boundaries.
- Fourier transform of spin density counts Floquet-Majorana modes.
- Method applicable in quantum engineered systems with moderate anisotropy.

## Abstract

Time periodic modulations of the transverse field in the closed XY spin-1/2 chain generate a very rich dynamical phase diagram, with a hierarchy of topological phases characterized by differing numbers of Floquet-Majorana modes. We show that this rich phase diagram survives when the system is coupled to dissipative end reservoirs. Circumventing the obstacle of preparing and measuring quasi energy configurations endemic to Floquet-Majorana detection schemes, we show that stroboscopic heat transport and spin density are robust observables to detect both the dynamical phase transitions and Majorana modes. In particular, we find that the derivative of the heat current, with respect to a control parameter, changes sign at the boundaries separating topological phases with different numbers of Floquet Majorana modes. We present a simple scheme to directly count the number of Floquet-Majorana modes in a phase from the Fourier transform of the local spin density profile. Our results are valid provided the anisotropies are not strong and can be easily implemented in quantum engineered systems.