Symmetry mismatch between SU(2) Hamiltonian and U(1) Liouvillian in a long-range XXZ chain with dephasing selects fast eigenmodes, enabling size-independent fast relaxation and a strong quantum Mpemba effect.
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Xuet al., Observation and Modulation of the Quantum Mpemba Effect on a Superconducting Quantum Processor, (2025), arXiv:2508.07707 [quant-ph]
16 Pith papers cite this work. Polarity classification is still indexing.
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Pith papers citing it
abstract
In non-equilibrium quantum systems, the quantum Mpemba effect (QME) emerges as a counterintuitive phenomenon: systems exhibiting greater initial symmetry breaking restore symmetry faster. It has been attracting broad interest in studying QME dynamics and potential applications in quantum information science. While theoretical exploration of QME has surged, experimental studies, specifically on its flexible modulation, remain limited. Here, we report the observation and modulation of QME using a superconducting processor featuring an all-to-all connected, tunable-coupling architecture that enables precise control from short- to long-range interactions. This platform allows independent manipulation of coupling regimes, on-site potentials, and initial states, enabling us to elucidate their roles in QME. To quantify symmetry restoration, we employ entanglement asymmetry (EA), derived from the reconstructed density matrix via quantum state tomography, as a sensitive probe. In strong short-range coupling regimes, EA crossovers during quenches from tilted N\'eel states confirm the presence of QME. In contrast, in intermediate coupling regimes, synchronized EA and entanglement entropy dynamics reveal the suppression of QME. Remarkably, QME reemerges with the introduction of on-site linear potentials or quenches from tilted ferromagnetic states, the latter proving robust against on-site disorder. Our study demonstrates flexible QME modulation on a superconducting platform with multiple controllable parameters, shedding light on quantum many-body non-equilibrium dynamics and opening avenues for quantum information applications.
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representative citing papers
Exact Fibonacci many-body scars engineered via soliton skeleton and invisible decorations in Rule-54 QCA, with finite translation orbits producing low-entanglement Floquet states.
In U(1)-symmetric random circuits, initial states with lower stabilizer Rényi entropy generate nonstabilizerness faster than those with higher entropy, with the effect also depending on spatial charge structure and extending to SU(2) circuits and Hamiltonian dynamics.
A new Gaussian asymmetry measure is defined that quantifies the minimal distance from a Gaussian state to the manifold of symmetric Gaussian states while capturing established dynamical signatures of entanglement asymmetry.
A transient symmetry-breaking evolution accelerates relaxation to equilibrium or ground states in quantum systems for both real and imaginary time dynamics under U(1) symmetry.
Resource-Markovianity is defined to operationally characterize resource Mpemba effects as breakdowns of this property under free relaxation dynamics in quantum resource theories.
In open quantum many-body systems with symmetry-breaking transitions, asymmetry dynamics produce a quantum Mpemba effect in the symmetric phase via non-monotonic evolution and an imbalance between increasing and decreasing asymmetry in the broken phase.
In a closed tripartite free-fermion setup, the central subsystem relaxes to the bath temperature without the Mpemba effect, with the relaxation fully characterised by generalised hydrodynamics.
More strongly entangled two-qubit states can lose entanglement faster than weaker ones under local amplitude damping due to excited-state population catalyzing sudden death.
Quenching the cavity decay rate in the Jaynes-Cummings model produces faster atomic excitation decay than constant dissipation, realizing the quantum Pontus-Mpemba effect.
In chaotic quantum systems with conservation laws, states initially farther from equilibrium can thermalize faster than closer ones via hydrodynamic relaxation differences, realizing the quantum Mpemba effect.
Analytical expressions are derived for external temperature protocols that produce any prescribed internal temperature trajectory using Newtonian cooling and microscopic models, including cases with Mpemba effects.
Entanglement asymmetry for inhomogeneous U(1) charges in fragmented systems scales extensively, is bounded by a universal fraction of its maximum, and distinguishes classical from quantum fragmentation.
Incorporating noise-induced quasiparticle correlations in the ν=1 QSSEP model yields the full-time distribution of entanglement entropy and shows the quantum Mpemba effect is extremely fine-tuned and hard to observe.
Entanglement asymmetry for space-inversion symmetry of free fermions on honeycomb lattices exhibits nonanalytic dependence on energy imbalance and persists after a quench to the symmetric point due to flat bands in certain geometries.
The paper demonstrates a quantum Mpemba-like effect during Unruh thermalization of a UDW detector and identifies maximum fidelity difference as a diagnostic distinguishing quantum Unruh thermalization from classical thermal bath effects.
citing papers explorer
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Symmetry-Protected Fast Relaxation and the Strong Quantum Mpemba Effect
Symmetry mismatch between SU(2) Hamiltonian and U(1) Liouvillian in a long-range XXZ chain with dephasing selects fast eigenmodes, enabling size-independent fast relaxation and a strong quantum Mpemba effect.
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Fibonacci many-body scars in a decorated Rule-54 quantum cellular automaton
Exact Fibonacci many-body scars engineered via soliton skeleton and invisible decorations in Rule-54 QCA, with finite translation orbits producing low-entanglement Floquet states.
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Nonstabilizerness Mpemba Effects
In U(1)-symmetric random circuits, initial states with lower stabilizer Rényi entropy generate nonstabilizerness faster than those with higher entropy, with the effect also depending on spatial charge structure and extending to SU(2) circuits and Hamiltonian dynamics.
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A Gaussian asymmetry measure
A new Gaussian asymmetry measure is defined that quantifies the minimal distance from a Gaussian state to the manifold of symmetric Gaussian states while capturing established dynamical signatures of entanglement asymmetry.
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Quantum Pontus-Mpemba Effects in Real and Imaginary-time Dynamics
A transient symmetry-breaking evolution accelerates relaxation to equilibrium or ground states in quantum systems for both real and imaginary time dynamics under U(1) symmetry.
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Operation Mpemba effect: Breakdown of resource-Markovianity of free dynamics
Resource-Markovianity is defined to operationally characterize resource Mpemba effects as breakdowns of this property under free relaxation dynamics in quantum resource theories.
-
Asymmetry dynamics and nonequilibrium symmetry-breaking phase transitions
In open quantum many-body systems with symmetry-breaking transitions, asymmetry dynamics produce a quantum Mpemba effect in the symmetric phase via non-monotonic evolution and an imbalance between increasing and decreasing asymmetry in the broken phase.
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A closed system setting for quantum thermalisation in free fermions
In a closed tripartite free-fermion setup, the central subsystem relaxes to the bath temperature without the Mpemba effect, with the relaxation fully characterised by generalised hydrodynamics.
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Anomalous Decay of Quantum Resources: The Entanglement Sudden Death Mpemba Effect
More strongly entangled two-qubit states can lose entanglement faster than weaker ones under local amplitude damping due to excited-state population catalyzing sudden death.
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Pontus-Mpemba effect in cavity quantum electrodynamics
Quenching the cavity decay rate in the Jaynes-Cummings model produces faster atomic excitation decay than constant dissipation, realizing the quantum Pontus-Mpemba effect.
-
Quantum Mpemba effect in chaotic systems with conservation laws
In chaotic quantum systems with conservation laws, states initially farther from equilibrium can thermalize faster than closer ones via hydrodynamic relaxation differences, realizing the quantum Mpemba effect.
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Inverse engineering of cooling protocols: from normal behavior to Mpemba effects
Analytical expressions are derived for external temperature protocols that produce any prescribed internal temperature trajectory using Newtonian cooling and microscopic models, including cases with Mpemba effects.
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Enhancing entanglement asymmetry in fragmented quantum systems
Entanglement asymmetry for inhomogeneous U(1) charges in fragmented systems scales extensively, is bounded by a universal fraction of its maximum, and distinguishes classical from quantum fragmentation.
-
Dynamics of entanglement fluctuations and quantum Mpemba effect in the $\nu=1$ QSSEP model
Incorporating noise-induced quasiparticle correlations in the ν=1 QSSEP model yields the full-time distribution of entanglement entropy and shows the quantum Mpemba effect is extremely fine-tuned and hard to observe.
-
Dynamics of entanglement asymmetry for space-inversion symmetry of free fermions on honeycomb lattices
Entanglement asymmetry for space-inversion symmetry of free fermions on honeycomb lattices exhibits nonanalytic dependence on energy imbalance and persists after a quench to the symmetric point due to flat bands in certain geometries.
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Quantum Mpemba-like effect in Unruh thermalization
The paper demonstrates a quantum Mpemba-like effect during Unruh thermalization of a UDW detector and identifies maximum fidelity difference as a diagnostic distinguishing quantum Unruh thermalization from classical thermal bath effects.