Non-Markovian Decay and Decoherence in Open Quantum Systems

Wei Cui

We study the optimal control problem in a non-Markovian open quantum system. The quantum system of interest is coupled to its local environment, which is dissipative in nature and tends to decay the quantum system. Based on the non-Markovian master equation, we study the non-Markovian effects on the system dynamics. The non-Markovian environment has dual effects on the quantum system: the dissipation and the backaction. The dissipation effect makes the system lose of quantum features, whereas the backaction revives it. We further design quantum control laws to control the system. The optimal control principle is studied to steer to quantum state to a target state. Finally, as an example, we used the optimal control method to control the quantum decoherence.

Carole Addis

Enrico Maresca

We propose an effective field-theoretic framework for open quantum systems in which decoherence dynamics are influenced by an auxiliary scalar field acting as an informational memory degree of freedom. This additional field induces intrinsically non-Markovian behavior, leading to structured noise spectra and deviations from standard exponential decay. The resulting reduced dynamics are governed by a non-local memory kernel, capturing temporal correlations beyond conventional approaches. We show that the model predicts oscillatory modulations in coherence decay and provides improved fits to simulated qubit data compared to both exponential and stretched-exponential models. The framework also reproduces nontrivial residual structures and spectral features that are not accounted for in standard decoherence theories. To test these predictions, we propose an experimental protocol using superconducting qubits, where systems initialized under identical environmental conditions but with different controlled histories exhibit distinguishable decoherence dynamics. This history dependence offers a potential experimental signature of the proposed mechanism. Overall, this work provides a phenomenological extension of decoherence theory and highlights the role of memory effects and informational degrees of freedom in open quantum systems, suggesting new directions for both theoretical and experimental investigation.

Jihong Cai, Advith Govindarajan, Marius Junge

The theory of open quantum systems served as a tool to prepare entanglement at the beginning stage of quantum technology and more recently provides an important tool for state preparation. Dynamics given by time dependent Lindbladians are Markovian and lead to decoherence, decay of correlation and convergence to equilibrium. In contrast Non-Markovian evolutions can outperform their Markovian counterparts by enhancing memory. In this letter we compare the trajectories of Markovian and Non-Markovian evolutions starting from a fixed initial value. It turns out that under mild assumptions every trajectory can be obtained from a family of time dependent Lindbladians. Hence Non-Markovianity is invisible if single trajectories are concerned.

Tomáš Mančal, Volkhard May

Heinz‐Peter Breuer