Entanglement asymmetry(EA) has emerged as a powerful tool for characterizing symmetry breaking in quantum many-body systems. In this Letter, we explore how symmetry is dynamically broken through the lens of EA in two ...Entanglement asymmetry(EA) has emerged as a powerful tool for characterizing symmetry breaking in quantum many-body systems. In this Letter, we explore how symmetry is dynamically broken through the lens of EA in two distinct scenarios: a non-symmetric Hamiltonian quench and a non-symmetric random quantum circuit, with a particular focus on U(1) symmetry. In the former case, symmetry remains broken in the subsystem at late times, whereas in the latter case, the symmetry is initially broken and subsequently restored, consistent with the principles of quantum thermalization. Notably, the growth of EA exhibits unexpected overshooting behavior at early times in both contexts, contrasting with the behavior of charge variance. We also consider dynamics of non-symmetric initial states under the symmetry-breaking evolution. Due to the competition of symmetry-breaking in both the initial state and Hamiltonian, the early-time EA can increase and decrease, while quantum Mpemba effects remain evident despite the weak symmetry-breaking in both settings.展开更多
Quantum many-body systems lie at the heart of modern fundamental physics.The study of these systems has revealed a plethora of fascinating phenomena,such as quantum thermalization,many-body localization,and quantum ma...Quantum many-body systems lie at the heart of modern fundamental physics.The study of these systems has revealed a plethora of fascinating phenomena,such as quantum thermalization,many-body localization,and quantum many-body scars.This review provides a comprehensive overview of the recent advances in understanding quantum many-body scars and non-ergodic dynamics in quantum systems on superconducting-circuit platforms,ranging from theoretical mechanisms and effective models to experimental observations.展开更多
We studied the dynamic correlations of non-integrable systems with quantum many-body scar(QMBS)states generated by a ladder operator.The ladder operator's spectral function has an exact δ-function peak induced by...We studied the dynamic correlations of non-integrable systems with quantum many-body scar(QMBS)states generated by a ladder operator.The ladder operator's spectral function has an exact δ-function peak induced by the QMBS states.As a concrete example,we show that in the one-dimensional(1D)spin-1 Affleck-Kennedy-Lieb-Tasaki model,the spectral function of two-magnon excitations exhibits a characteristic bowtie shape composed of aδ-function resonance peak at momentum k=π and a continuum spectrum elsewhere.The two-magnon excitations can be observed via resonant inelastic X-ray scattering spectroscopy on quasi-1D nickelates and other spin-1 antiferromagnetic materials.Therefore,the findings of this study pave the way for detecting(approximate)QMBS states in realistic materials.展开更多
基金the support of the International Young Scientist Fellowship of the Institute of Physics,Chinese Academy of Sciences (Grant No.202407)supported by the Innovation Program for Quantum Science and Technology (Grant No.2024ZD0301700)+1 种基金the start-up grant at IOP-CAS.ZXL is supported by the Beijing Natural Science Foundation (Grant No.JR25007)the National Natural Science Foundation of China (Grants No.12347107and 12474146)。
文摘Entanglement asymmetry(EA) has emerged as a powerful tool for characterizing symmetry breaking in quantum many-body systems. In this Letter, we explore how symmetry is dynamically broken through the lens of EA in two distinct scenarios: a non-symmetric Hamiltonian quench and a non-symmetric random quantum circuit, with a particular focus on U(1) symmetry. In the former case, symmetry remains broken in the subsystem at late times, whereas in the latter case, the symmetry is initially broken and subsequently restored, consistent with the principles of quantum thermalization. Notably, the growth of EA exhibits unexpected overshooting behavior at early times in both contexts, contrasting with the behavior of charge variance. We also consider dynamics of non-symmetric initial states under the symmetry-breaking evolution. Due to the competition of symmetry-breaking in both the initial state and Hamiltonian, the early-time EA can increase and decrease, while quantum Mpemba effects remain evident despite the weak symmetry-breaking in both settings.
基金supported by the Zhejiang Provincial Natural Science Foundation of China(No.LD25A050002)the National Natural Science Foundation of China(No.12375021)the National Key Research and Development Program of China(No.2022YFA1404203).
文摘Quantum many-body systems lie at the heart of modern fundamental physics.The study of these systems has revealed a plethora of fascinating phenomena,such as quantum thermalization,many-body localization,and quantum many-body scars.This review provides a comprehensive overview of the recent advances in understanding quantum many-body scars and non-ergodic dynamics in quantum systems on superconducting-circuit platforms,ranging from theoretical mechanisms and effective models to experimental observations.
基金supported by the National Natural Science Foundation of China(Grant No.12174387)the Chinese Academy of Sciences(Grant Nos.YSBR-057 and JZHKYPT-2021-08)the Innovative Program for Quantum Science and Technology(Grant No.2021ZD0302600)。
文摘We studied the dynamic correlations of non-integrable systems with quantum many-body scar(QMBS)states generated by a ladder operator.The ladder operator's spectral function has an exact δ-function peak induced by the QMBS states.As a concrete example,we show that in the one-dimensional(1D)spin-1 Affleck-Kennedy-Lieb-Tasaki model,the spectral function of two-magnon excitations exhibits a characteristic bowtie shape composed of aδ-function resonance peak at momentum k=π and a continuum spectrum elsewhere.The two-magnon excitations can be observed via resonant inelastic X-ray scattering spectroscopy on quasi-1D nickelates and other spin-1 antiferromagnetic materials.Therefore,the findings of this study pave the way for detecting(approximate)QMBS states in realistic materials.
