Quantum many-body mixed phase space revealed by hybrid feedback control
Abstract
Understanding how complex systems transition between order and chaos is a central challenge of nonequilibrium physics. While weak perturbations of classical integrable systems give rise to a mixed phase space of coexisting regular and chaotic trajectories, analogous behavior in interacting quantum many-body systems has remained elusive. Here we develop and experimentally implement a hybrid quantum-classical feedback protocol that autonomously discovers and stabilizes long-lived regular trajectories in a superconducting quantum processor. Each iteration combines short-time quantum evolution with classical optimization that projects the dynamics back onto a low-entanglement variational manifold, effectively distilling coherence from chaotic evolution. The stabilized trajectories reveal a quantum many-body mixed phase space emerging from nonlinear variational dynamics, without a direct analogue in classical or few-body quantum systems. Our results establish a versatile framework for algorithmic discovery and control of coherent dynamics previously inaccessible to experiment.
Versions
Related
- Measurement-Based Feedback of Open Quantum Systems: A Control-Theoretic Review and Tutorial
- Bypassing no-go theorems on mixed classical-quantum systems: the (counter)example of hybrid van Hove theory
- Hybrid Quantum-Classical Optimization for Emergency-Priority Traffic Signal Control
- Structural control of two-level defect density revealed by high-throughput correlative measurements of Josephson junctions
- The Evolution of Electronic Structure in Conjugated Molecules Revealed by Mixed-Reference Spin-Flip Time-Dependent Density Functional Theory and Density-Based Analyses: I. Polyenes
BibTeX
@misc{dong2026quantum,
title = {{Quantum many-body mixed phase space revealed by hybrid feedback control}},
author = {Hang Dong and Jie Ren and Andrew Hallam and Han Wang and Zhengyi Cui and Yiren Zou and Junlin Wang and Hekang Li and Qiujiang Guo and Zhen Wang and Lei Ying and Zlatko Papic},
howpublished = {arXiv},
year = {2026},
month = jul,
doi = {10.48550/arxiv.2607.14223},
eprint = {2607.14223},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2607.14223},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Quantum many-body mixed phase space revealed by hybrid feedback control
AU - Hang Dong
AU - Jie Ren
AU - Andrew Hallam
AU - Han Wang
AU - Zhengyi Cui
AU - Yiren Zou
AU - Junlin Wang
AU - Hekang Li
AU - Qiujiang Guo
AU - Zhen Wang
AU - Lei Ying
AU - Zlatko Papic
PY - 2026
DA - 2026/07/15
PB - arXiv
DO - 10.48550/arxiv.2607.14223
UR - https://arxiv.org/abs/2607.14223
AB - Understanding how complex systems transition between order and chaos is a central challenge of nonequilibrium physics. While weak perturbations of classical integrable systems give rise to a mixed phase space of coexisting regular and chaotic trajectories, analogous behavior in interacting quantum many-body systems has remained elusive. Here we develop and experimentally implement a hybrid quantum-classical feedback protocol that autonomously discovers and stabilizes long-lived regular trajectories in a superconducting quantum processor. Each iteration combines short-time quantum evolution with classical optimization that projects the dynamics back onto a low-entanglement variational manifold, effectively distilling coherence from chaotic evolution. The stabilized trajectories reveal a quantum many-body mixed phase space emerging from nonlinear variational dynamics, without a direct analogue in classical or few-body quantum systems. Our results establish a versatile framework for algorithmic discovery and control of coherent dynamics previously inaccessible to experiment.
ER -