Decoherence of a dissipative Brownian charged magneto-anharmonic oscillator: an information theoretic approach

TL;DR

This paper investigates how anharmonicity and magnetic fields influence decoherence in a dissipative quantum oscillator, using an information-theoretic approach, with implications for quantum technology and experimental testing.

Contribution

It introduces a perturbative solution for a dissipative anharmonic oscillator in a magnetic field and derives a non-Markovian master equation considering anharmonic effects.

Findings

Anharmonicity accelerates decoherence due to deconfining effects.

Oscillatory heating function indicates information backflow.

Von-Neumann entropy increases with anharmonicity, confirming deconfinement.

Abstract

We study the decoherence of an anisotropic anharmonic oscillator in a magnetic field, coupled to a bath of harmonic oscillators at high and low temperatures. We solve the anharmonic oscillator problem using perturbative techniques and derive the non-Markovian master equation in the weak coupling limit. The anharmonicity parameter {\alpha} enhances decoherence due to the deconfining effect of anharmonicity. The oscillatory nature of the time evolution of heating function indicates information backflow. The von-Neumann entropy is also calculated for the system, which increases with {\alpha}, consistent with the deconfining effect noted in the decoherence analysis. We have also proposed a cold ion experimental set up for testing our theoretical predictions. The study is of relevance to the domain of quantum technology where decoherence significantly affects the performance of a quantum computer.