Quantum control and robust quantum information

Juju Hu, Qiang Ke, Yinghua Ji

Quantum control is responsible for many key problems in quantum information processing such as engineering quantum state and quantum gate, suppressing decoherence, etc. The research on quantum control will greatly advance the development of quantum information science. The uncertainties exist in quantum systems also causes decoherence, which will destroy systems' excellent quantum properties. Hence it is significant to study robust control of open quantum system to enhance control performance in reality. In this paper, based on the robust control method for quantum systems, we investigate robustness control strategies against uncertainties under three classical environments by taking an eigenstate of the two-level quantum system as a sliding mode, and acquire the corresponding analytical expression of sampling period based on data sampling. Furthermore, the influences of temperature and squeezing parameter on the sampling period are analyzed.

Paul W. Brumer, Daniel A. Lidar, H-K Lo +1 more

Ghaieth Hezzi, Ghassen Dridi

Coherent quantum control shows promise in preparing and manipulating internal states within a quantum system coherently. Specifically, it aims to smoothly transition the system from an initial state to a desired target state using external electromagnetic fields. This transfer of population between ground states is crucial in various quantum processes, including applications in photochemistry for controlling reactions with fast laser fields, enhancing Nuclear Magnetic Resonance images, quantum optics and quantum information science. Quantum information processing manipulates data with unitary operators called quantum logic gates, which control state transitions in qubits. These gates are vital for future quantum computers, requiring high efficiency and robustness despite experimental limitations and errors, like inconsistent control fields. The primary goal in quantum computing is to transfer population from the ground state to the target state with a high fidelity , good robustness and minimum interaction time between the electromagnetic fields and the system. Currently, creating a control method that meets all three criteria is a significant challenge in quantum information. However, by merging reverse engineering using the Lewis-Riesenfeld dynamic invariant with optimal control theory, we've shown that designing such a control field can be simplified into a Lagrange optimization problem with integral constraints. This hybrid method, called RIO (Robust Inverse Optimization), is adaptable and applicable to diverse quantum control challenges.

PNG WEN HAN

m el-rakhawi

Elـrakhawi Framework for Geometrically-Informed Quantum Control of Femtosecond Molecular Dynamics: An AI-Driven Approach to Robust Coherent Control in Open Quantum Systems

将光 坂東, 翼 市川, 近藤 康 +1 more