New approach for solving master equation of open atomic system

TL;DR

The paper introduces the KBES method, a novel approach converting master equations into Schrödinger-like form, enabling exact solutions for various open atomic systems and facilitating computational analysis.

Contribution

The KBES method provides a universal, computer-friendly way to solve master equations for finite-level quantum systems, surpassing previous super-operator techniques.

Findings

Exact dynamics of a damped 2-level atom in a time-dependent field

Solution of a 3-level atom coupled with a bath

Resolution of N-qubits Heisenberg chain master equation

Abstract

We describe a new approach called Ket-Bra Entangled State (KBES) Method which enables one convert master equations into Schr\"odinger-like equation. In sharply contrast to the super-operator method, the KBES method is applicable for any master equation of finite-level system in theory, and the calculation can be completed by computer. With this method, we obtain the exact dynamic evolution of a radioactivity damped 2-level atom in time-dependent external field, and a 3-level atom coupled with bath; Moreover, the master equation of N-qubits Heisenberg chain each qubit coupled with a reservoir is also resolved in Sec.III; Besides, the paper briefly discuss the physical implications of the solution.