A memory-information window in finite-duration quantum control
Abstract
Environmental noise is a major source of decoherence and errors in quantum systems. In a non-Markovian environment, the noise has a finite correlation time, and the system can retain information about its previous interactions with the environment. Here, we investigate how such environmental memory can be observed through a finite-duration coherent quantum operation. Coherent control dynamically reshapes the stochastic coupling operator and thereby changes how two-time noise correlations affect the quantum process. For Ornstein-Uhlenbeck noise, we show analytically that two different limits reduce the information on the correlation time. In the short-memory limit, the leading dynamics depend on the integrated-noise combination σ/τc, where σ is the noise variance and τc is the correlation time, making these parameters locally degenerate. In the long-memory limit, the stochastic field becomes quasi-static during the operation, and sensitivity to the correlation time is suppressed. Exact stochastic simulations for a driven single-qubit Xπ rotation and a two-qubit exchange gate show that independent correlation-time information becomes largest between these limits, when the environmental and control timescales are comparable. Noncommuting controls enhance this information, whereas commuting controls do not. Simulations at different gate durations tg further show that the information window approximately follows the dimensionless correlation ratio τc/tg. These results provide a timescale-matching principle for probing finite-correlation non-Markovian noise with coherent quantum control.
Related
- Plasmon-assisted coherent control of a four-level semiconductor quantum dot: operating window and fidelity limits
- Information flow control in hybrid quantum networks
- Quantum memory in an effective Λ-type system using dynamic detuning control of a superconducting qubit pair
- Memory dimension detection in open quantum dynamics via pseudo-control
- Information Thresholds in Adaptive Quantum Control of Nonadiabatic Molecular Dynamics:
BibTeX
@misc{doyeol2026memoryinformation,
title = {{A memory-information window in finite-duration quantum control}},
author = {Doyeol and Ahn},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.21380},
eprint = {2609.21380},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.21380},
}
RIS
TY - UNPB
TI - A memory-information window in finite-duration quantum control
AU - Doyeol
AU - Ahn
PY - 2026
DA - 2026/09/18
PB - arXiv
DO - 10.48550/arxiv.2609.21380
UR - https://arxiv.org/abs/2609.21380
AB - Environmental noise is a major source of decoherence and errors in quantum systems. In a non-Markovian environment, the noise has a finite correlation time, and the system can retain information about its previous interactions with the environment. Here, we investigate how such environmental memory can be observed through a finite-duration coherent quantum operation. Coherent control dynamically reshapes the stochastic coupling operator and thereby changes how two-time noise correlations affect the quantum process. For Ornstein-Uhlenbeck noise, we show analytically that two different limits reduce the information on the correlation time. In the short-memory limit, the leading dynamics depend on the integrated-noise combination σ/τc, where σ is the noise variance and τc is the correlation time, making these parameters locally degenerate. In the long-memory limit, the stochastic field becomes quasi-static during the operation, and sensitivity to the correlation time is suppressed. Exact stochastic simulations for a driven single-qubit Xπ rotation and a two-qubit exchange gate show that independent correlation-time information becomes largest between these limits, when the environmental and control timescales are comparable. Noncommuting controls enhance this information, whereas commuting controls do not. Simulations at different gate durations tg further show that the information window approximately follows the dimensionless correlation ratio τc/tg. These results provide a timescale-matching principle for probing finite-correlation non-Markovian noise with coherent quantum control.
ER -