This universal tendency toward thermalization stands as a formidable barrier in quantum control and simulation. It erodes the distinctive quantum correlations crucial for advanced quantum technological applications, making it imperative to decipher the timescales and mechanisms underlying the heating dynamics. While it is known that periodic driving at high frequencies can retard the heating process, the behavior under more complex and non-periodic driving protocols remains largely uncharted. Scientists have sought to unravel whether these more intricate driving schemes might either enhance or fundamentally alter the way quantum systems traverse toward equilibrium.

In a groundbreaking experiment, a collaboration spearheaded by researchers at the Institute of Physics of the Chinese Academy of Sciences employed a state-of-the-art quantum processor, Chuang-tzu 2.0, to probe these subtle dynamics with unprecedented precision. The processor, composed of an impressive 78 superconducting qubits arranged in a two-dimensional 6×13 lattice and interconnected via 137 tunable couplers, serves as a versatile platform for exploring many-body quantum phenomena. This architecture allowed for exquisite control and monitoring of the quantum states across a large system embodying a regime where classical simulations become infeasible.

The experiment initiated the system in a carefully prepared density-wave configuration, a highly ordered quantum state exhibiting alternating populations of particles. The system was then subjected to a sequence of control pulses characterized by random multipolar driving—a protocol defined by two key parameters: the order of the driving, which reflects the complexity of the applied pulse patterns, and the temporal length of each driving unit. This approach extended far beyond conventional periodic driving, introducing a stochastic structure in time that challenged existing theories.

By meticulously tracking observables such as the particle-number imbalance and the growth of entanglement entropy as the system evolved through up to 1,000 driving cycles, the researchers gained striking insights into the energy absorption process. Rather than succumbing immediately to thermalization, the quantum system exhibited a pronounced prethermal plateau—a temporal regime in which entropy and particle imbalance remained largely static, indicating the system’s resistance to scrambling and energy homogenization. This prethermal state persisted significantly longer than anticipated, effectively delaying the onset of chaotic thermal behavior.

The researchers uncovered that the lifetime of this prethermal plateau was not fixed but could be finely tuned through the parameters controlling the driving dynamics. Astonishingly, the duration of this regime obeyed a robust power-law scaling tied directly to the driving frequency and the random driving order, with the exponent following a universal form proportional to (2n + 1), n being the driving order. This relationship establishes a profound link between the microscopic temporal structure of the applied drive and the macroscopic thermalization timescale, providing a new lens to investigate controlled heating in complex quantum systems.

Delving deeper, the team observed that beyond the prethermal plateau, the system’s entanglement expanded across the lattice with a strong volume-law scaling—an indication that quantum correlations extended extensively over the entire processor. This regime marks a domain where classical computational tools, such as tensor-network simulations, become severely limited, underscoring the immense complexity and richness of many-body quantum dynamics in driven settings. The emergence of such volumetric entanglement suggests that large-scale, stochastic driving protocols open new pathways for exploring regimes inaccessible by existing numerical algorithms.

This research significantly advances the theoretical and experimental frontier of non-equilibrium quantum physics. By moving beyond periodic and quasi-periodic drives to embrace random multipolar protocols, scientists now have a novel framework for probing thermalization in quantum many-body systems. The discovery of a tunable prethermal plateau with a universal scaling exponent not only challenges current theoretical models but also sets stringent constraints for developing comprehensive descriptions of driven quantum matter.

Furthermore, the insights gleaned from the Chuang-tzu 2.0 processor reflect an ever-widening gap between the experimental capabilities of quantum simulators and the reach of classical computational resources. As entanglement spread and complexity bloom in these large-scale quantum systems, classical simulations falter. This disparity highlights the urgent necessity for quantum platforms to investigate long-time quantum dynamics, which hold the key to unlocking next-generation quantum technologies and deepening our understanding of fundamental quantum processes.

In sum, the seminal experiment conducted on the 78-qubit Chuang-tzu 2.0 processor illuminates the intricate interplay between structured random driving protocols and heating dynamics in many-body quantum systems. The identification of a long-lived prethermal regime and its scaling behavior represents a pivotal step in controlling and harnessing non-equilibrium quantum phenomena. This work paves the way for future explorations into thermalization mechanisms, quantum information preservation, and the design of robust quantum simulators that can reliably operate under complex, non-periodic driving conditions.

The study, published in the prestigious journal Nature on January 28, 2026, stands as a testament to the power of large-scale superconducting quantum processors in addressing foundational questions in quantum physics. Its findings not only deepen our understanding of how energy and coherence evolve in driven quantum systems but also push the boundaries of what experimental quantum science can achieve in modeling and controlling complex many-body dynamics over extended temporal horizons.

Subject of Research: Quantum computing, driven many-body quantum systems, non-equilibrium physics, thermalization dynamics

Article Title: Prethermalization by random multipolar driving on a 78-qubit processor

News Publication Date: 28-Jan-2026

Web References: https://www.nature.com/articles/s41586-025-09977-x

References: DOI 10.1038/s41586-025-09977-x

Keywords: Quantum processors, non-equilibrium dynamics, prethermalization, quantum thermalization, entanglement entropy, random multipolar driving

Until now, investigations of the quantum Mpemba effect have predominantly focused on paradigmatic quantum systems prone to thermalization—where subsystems eventually reach thermal equilibrium. These studies elucidated how counterintuitive dynamical signatures emerge from subtle interplays between symmetry breaking and unitary evolution in thermalizing environments. However, an intriguing question has lingered, unresolved: can the quantum Mpemba effect survive in the rugged realms of many-body localization (MBL)? In contrast to thermalizing systems, MBL systems exhibit robust resistance to thermal equilibration owing to intrinsic disorder, freezing dynamics in a non-ergodic phase. This setting seemingly defies thermal intuition and raises fundamental challenges about nonequilibrium quantum phenomena, positioning MBL as a pivotal platform to test the universality and robustness of the QME beyond traditional thermodynamic confines.

Groundbreaking new research, recently published in Science Bulletin, illuminates this frontier by demonstrating that the quantum Mpemba effect not only persists within MBL systems but does so through an entirely distinct physical framework. The research team formulated an innovative theoretical structure to characterize symmetry restoration dynamics uniquely intrinsic to MBL phases, highlighting how subsystem symmetries, despite disorder-induced localization, can still be dynamically reinstated. Leveraging the effective l-bit model—a theoretical tool capturing localized integrals of motion—the authors carried out extensive numerical simulations that substantiated the counterintuitive phenomenon: states exhibiting greater initial symmetry breaking recover their symmetric configurations more swiftly than less broken counterparts. This hallmark signature confirms the presence of the quantum Mpemba effect deeply embedded within the fabric of non-thermalizing MBL physics.

Intriguingly, the quantum Mpemba effect in MBL systems diverges fundamentally from its thermal system analog. Whereas in thermal environments the QME reflects an accelerated convergence to equilibrium akin to “hot water freezing faster,” the phenomenon in localized systems evokes a metaphor of “thick syrup” resistant to mixing or flow. Despite the apparent rigidity and slow dynamics characteristic of MBL phases, paradoxically, “hotter” localized states still manage to “freeze” or restore symmetry more rapidly. This novel non-thermal mechanism reveals profound insights into the dynamics of disorder-protected quantum states and provides a powerful diagnostic criterion for assessing the stability and nature of many-body localized phases—domains where conventional thermodynamic intuition fails utterly.

Beyond its conceptual elegance, the discovery of the QME in many-body localized systems has significant implications for the broader understanding of quantum relaxation phenomena. It suggests that quantum systems defying thermalization can nonetheless exhibit rich and unexpected dynamical behaviors, governed by mechanisms fundamentally distinct from classical or thermal scenarios. This opens fresh theoretical vistas into how quantum information and correlations evolve in complex disordered landscapes, with potential ramifications for quantum statistical mechanics, condensed matter physics, and the emergent theory of nonequilibrium quantum phases.

Moreover, the new theoretical framework and computational evidence pave the way for experimental verification of the quantum Mpemba effect in disordered quantum simulators and quantum computing platforms. Ultracold atoms, trapped ions, and superconducting qubit arrays—systems capable of realizing controlled MBL phases—now emerge as promising arenas to observe symmetry restoration dynamics and explore the QME experimentally. Such explorations could not only validate theoretical predictions but also inspire innovative quantum control protocols exploiting disorder-protected states for robust quantum information processing, error correction, and quantum thermodynamics research.

The collaborative study was conducted by researchers from Tsinghua University, the Institute of Physics of the Chinese Academy of Sciences, and Sun Yat-sen University. These institutions brought together expertise spanning theoretical condensed matter physics, quantum information theory, and computational physics to unravel the subtle interplay between disorder, symmetry breaking, and quantum dynamics. The work received substantial support from the National Natural Science Foundation of China, the Ministry of Science and Technology of China, and the New Cornerstone Science Foundation through the Xplorer Prize, underscoring the significance and interdisciplinary appeal of the findings.

At the heart of the research lies the concept of symmetry restoration—a fundamental aspect of quantum dynamics where initially broken symmetries in a subsystem return to equilibrium values over time. In MBL systems, localization impedes conventional thermal relaxation, yet the study shows that symmetry restoration is governed by localized integrals of motion (“l-bits”) that encode memory of the initial conditions. The QME manifests as a faster trajectory toward symmetry establishment for states harboring greater initial asymmetry, a finding that challenges preexisting paradigms linking relaxation speed to proximity to equilibrium.

This research not only reconciles the presence of the QME with the absence of global thermalization in MBL phases but also enriches the theoretical toolkit used to describe quantum non-ergodic systems. The l-bit formalism, combined with sophisticated numerical methods, provides a precise and versatile platform to capture emergent dynamical behaviors, including intricate interference and dephasing effects responsible for the observed quantum Mpemba phenomenon. Such advances deepen fundamental understanding of quantum matter’s behavior under extreme conditions of disorder and coherence.

In summary, the extended exploration of the quantum Mpemba effect within many-body localization systems unveils groundbreaking insights into the nature of quantum relaxation and symmetry dynamics beyond the equilibrium paradigm. It reveals a novel non-thermal pathway by which asymmetric quantum states regain symmetry more rapidly, even in systems long thought to be dynamically frozen and non-thermalizing. This work not only bridges a critical gap in the understanding of quantum Mpemba effects but also uncovers tantalizing possibilities for future experimental realizations and applications in quantum technologies, marking a milestone in the study of complex quantum phenomena.

Subject of Research: Quantum Mpemba Effect and Symmetry Restoration in Many-Body Localization Systems

Article Title: Symmetry Restoration and Quantum Mpemba Effect in Many-Body Localization Systems

News Publication Date: Not explicitly provided; inferred as current within 2025

Web References: DOI Link to Article

Image Credits: ©Science China Press

Keywords

Quantum Mpemba effect, many-body localization, symmetry restoration, quantum thermalization, non-ergodic systems, l-bit model, nonequilibrium dynamics, quantum relaxation, disorder, quantum coherence, quantum simulation, quantum computing