Scientists have long been fascinated by the intricate behavior of quantum systems subjected to external driving forces. These forces—ranging from ultrafast laser and microwave pulses to oscillating electric and magnetic fields, as well as finely tuned voltages and currents—are crucial tools for pushing quantum technology forward. They enable the exploration of exotic quantum phases, the control of qubits in quantum computation, and even the simulation of materials that defy classical intuition. However, a pivotal challenge has emerged in this quest: driven quantum systems tend to absorb energy continuously from these external stimuli, inevitably heating up to an infinite-temperature phase where all quantum coherence and rich structural information are lost.
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
