Fischer Information of a Nonequilibrium Anharmonic Donor-Acceptor Rectifier

TL;DR

This paper explores the quantum Fisher information in a nonequilibrium anharmonic donor-acceptor rectifier, analyzing parameter estimation precision for energies and vibrational modes using a quantum master equation.

Contribution

It introduces a detailed analysis of parameter estimation in a quantum rectifier with anharmonic vibrational modes, highlighting optimal estimation times and conditions for different parameters.

Findings

Optimal time exists for estimating donor and acceptor energies.

Steady-state conditions improve vibrational frequency estimation.

Acceptor energy is most precisely estimable, especially under strong coupling.

Abstract

We investigate a nonequilibrium donor-acceptor quantum rectifier system coupled to an anharmonic vibrational mode, treating the vibrational dynamics both as a two-level system and as multilevel system. The time-dependent Fischer information is then calculated by deriving a quantum master equation for the reduced system dynamics. We estimate some key rectifier parameters, the donor energy, the acceptor energy, and the vibrational frequency. We report that there is an optimal time for estimating the donor and acceptor energy. However, the anharmonic mode can be estimated better only in the steadystate. The acceptor energy is found to be most precisely estimable, especially under strong coupling and high bias. Donor energy shows limited sensitivity, while vibrational frequency estimation benefits from low temperatures. This work offers a theoretical foundation for enhancing parameter estimation in nanoscale quantum devices, guiding future sensing and metrological applications in quantronic systems.