Article
Physics, Fluids & Plasmas
Camille L. Latune
Summary: The study compares two strategies for obtaining (approximately) steady states in strong coupling regime and finds that their predictions coincide in many situations. The successful testing of validity criteria helps determine the range of validity for both strategies.
Article
Chemistry, Physical
Min Du, Ming Qin, Haitao Cui, Chunyang Wang, Yuqing Xu, Xiaoguang Ma, Xuexi Yi
Summary: This study investigates the effects of spatial correlations on the dynamics of excitation energy transfer in photosynthetic light-harvesting complexes. Experimental findings suggest that spatially correlated environmental fluctuations can lead to long-lived quantum coherent energy transfer, with a nonequilibrium initial bath condition and spatial correlations interacting to open up new energy transfer pathways and protect coherence. The research also demonstrates the versatility of the polaron master equation approach in studying dynamics in subsystems of complex systems.
JOURNAL OF PHYSICAL CHEMISTRY B
(2021)
Article
Optics
V. A. Mikhailov, N. Troshkin
Summary: The paper explores the non-Markovian evolution of a two-level system (qubit) influenced by three independent decoherence channels, two of which have a classical nature from interaction with a stochastic field, and the third is a quantum channel formed by interaction with a bosonic bath. The impact of modifying the spectral densities of the channels on the steady states of the two-level system, evolution of its density matrix, and equilibrium emission spectra is studied. Furthermore, the impact of applying the rotation-wave approximation to the bath channel on the accuracy of the results is investigated.
Article
Chemistry, Physical
Tatsushi Ikeda, Akira Nakayama
Summary: This article presents a new representation of the hierarchical equations of motion (HEOM) theory, mapping the hierarchy into a continuous space using the quantum Fokker-Planck equation. The new representation provides a rigorous time evolution of the bath coordinate distribution and is more stable and efficient, especially for systems with strong system-bath coupling.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Physics, Multidisciplinary
Marten Richter, Stephen Hughes
Summary: The study extended the algorithm for quantum path integrals using tensor networks to open quantum systems with off-diagonal coupling. Demonstrating this approach on a coupled cavity waveguide system also hints at potential applications in other areas.
PHYSICAL REVIEW LETTERS
(2022)
Article
Optics
S. Wenderoth, H. -P. Breuer, M. Thoss
Summary: In general, a small system in contact with a macroscopic environment will approach an asymptotic state, mainly determined by macroscopic properties of the environment. However, in certain situations, the asymptotic state of the system is influenced by its initial state, retaining some information about it indefinitely. In this study, we propose a measure to quantify the influence of the initial state on the dynamics of an open system, derive conditions for the existence and uniqueness of the asymptotic state, and demonstrate its application through the spin-boson model. We identify three qualitatively distinct long-time behaviors and discuss how they can be characterized using the proposed measure.
Article
Physics, Multidisciplinary
Giorgio Zicari, Baris cakmak, Ozguer E. Mustecaplioglu, Mauro Paternostro
Summary: Recent studies have found that figures of merit in thermodynamics, such as work, heat, and entropy production, are intrinsically dependent on the presence of quantum coherences in a system. However, it is still unclear whether coherences hinder or enhance the thermodynamic performance. Our research demonstrates that there is no general monotonic relationship between entropy production and the degree of quantum coherence in a bipartite quantum system undergoing non-unitary channels. The correspondence between these quantities can only be established under specific conditions. This highlights the need for a systematic study on how genuine quantum features affect the non-equilibrium thermodynamics of quantum processes.
NEW JOURNAL OF PHYSICS
(2023)
Article
Chemistry, Physical
Yao Wang, Zi-Hao Chen, Rui-Xue Xu, Xiao Zheng, YiJing Yan
Summary: This study describes the Gaussian environmental dissipative effect in open quantum systems using statistical quasi-particles called dissipatons, and establishes the dissipaton thermofield theory. The generalized Langevin dynamics of absorptive and emissive thermofield operators are effectively noise-resolved and numerically validated. An important entanglement theorem between a specific class of nonequilibrium steady-state correlation functions is derived, and the expression for transport current is obtained, recovering the result from the nonequilibrium Green's function formalism.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Lipeng Chen, Yiying Yan, Maxim F. Gelin, Zhiguo Lue
Summary: The dynamics of the (sub-)Ohmic spin-boson model under different bath initial conditions were investigated using the Dirac-Frenkel time-dependent variational approach with the multiple Davydov D-1 Ansatz in the interaction picture. The validity of the approach was confirmed by comparing the results with those of the hierarchy equations of motion method. The phase diagrams for different bath initial conditions were identified by analyzing the features of nonequilibrium dynamics. It was found that the initial preparation of the bath significantly influenced the dynamics.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Multidisciplinary Sciences
E. Garlatti, A. Albino, S. Chicco, V. H. A. Nguyen, F. Santanni, L. Paolasini, C. Mazzoli, R. Caciuffo, F. Totti, P. Santini, R. Sessoli, A. Lunghi, S. Carretta
Summary: Understanding phonon-induced relaxation in molecular qubits is crucial for their application potential. Garlatti et al. utilize inelastic X-ray scattering and density functional theory to investigate the role of low-energy phonons on spin relaxation in a prototypical molecular qubit. They find that intra-molecular vibrations with very-low energies are largely responsible for spin relaxation up to ambient temperature. This research provides insights into improving spin coherence and opens new avenues for the investigation of magnetic molecules for quantum devices.
NATURE COMMUNICATIONS
(2023)
Article
Computer Science, Interdisciplinary Applications
Zhenning Cai, Jianfeng Lu, Siyao Yang
Summary: We present fast algorithms for the summation of Dyson series and the inchworm Monte Carlo method for quantum systems coupled with harmonic baths. The algorithms are based on evolving the integro-differential equations, with the most expensive part being the computation of bath influence functionals. To accelerate the computation, we design fast algorithms that reuse the previously computed bath influence functionals, reducing the number of calculations. It is proven that these fast algorithms reduce the number of such calculations by a factor of O(N), where N is the total number of time steps. Numerical experiments are conducted to demonstrate the efficiency of the method and validate the theoretical results.
COMPUTER PHYSICS COMMUNICATIONS
(2022)
Article
Chemistry, Physical
Christian Sigl, Elena M. Willner, Wouter Engelen, Jessica A. Kretzmann, Ken Sachenbacher, Anna Liedl, Fenna Kolbe, Florian Wilsch, S. Ali Aghvami, Ulrike Protzer, Michael F. Hagan, Seth Fraden, Hendrik Dietz
Summary: This study introduces a programmable icosahedral canvas for the self-assembly of icosahedral shells with viral trapping and antiviral properties. It demonstrates the potential of a new broad-spectrum antiviral platform that could alleviate many threats to global public health.
Article
Astronomy & Astrophysics
S. P. Baranov, A. Lipatov, A. A. Prokhorov
Summary: We study the process of double J/psi production in pp collisions at the LHC using the k(T)-factorization approach. The gluon fragmentation mechanism and the effects of multiple gluon emission are shown to be crucial for the production of J/psi pairs in both single- and multiparton interaction processes.
Article
Chemistry, Multidisciplinary
Christopher R. Greve, Meike Kuhn, Fabian Eller, Michael A. Buchhorn, Alexander Hexemer, Guillaume Freychet, Lutz Wiegart, Eva M. Herzig
Summary: X-ray photon correlation spectroscopy (XPCS) is a versatile tool for measuring dynamics in bulk samples on the nanometer to micrometer scale. This paper investigates the impact of reflection and refraction effects on the correlation analysis in grazing incidence (GI) scattering experiments. By measuring both grazing incidence transmission XPCS (GT-XPCS) and grazing incidence XPCS (GI-XPCS), the main contributions of the detected signal and the limitations for data interpretation are identified.
Article
Multidisciplinary Sciences
Ye-Ryoung Lee, Dong-Young Kim, Yonghyeon Jo, Moonseok Kim, Wonshik Choi
Summary: This study presents a volumetric image reconstruction framework that combines the wavelength and propagation angles of light waves to better deal with multiple scattering. By simultaneously scanning the wavelength and illumination angle of the light source, the use of signal waves is increased 32-fold compared to existing 2D-based methods, achieving ultrahigh volumetric resolution even within complex scattering medium.
NATURE COMMUNICATIONS
(2023)
Article
Physics, Multidisciplinary
Zheng-An Wang, Yi Peng, Dapeng Yu, Heng Fan
Summary: The metrology scheme reported involves measuring the magnetic susceptibility of an atomic spin ensemble in the x and z directions, producing parameter estimation that exceeds the standard quantum limit. The scheme is robust against measurement fluctuation caused by environmental noise and defects, providing precise estimation of phi based on the number of atomic spins.
Article
Physics, Multidisciplinary
Shou-Kuan Zhao, Zi-Yong Ge, Zhong-Cheng Xiang, Guang-Ming Xue, Hai-Sheng Yan, Zi-Ting Wang, Zhan Wang, Hui-Kai Xu, Fei-Fan Su, Zhao-Hua Yang, He Zhang, Yu-Ran Zhang, Xue-Yi Guo, Kai Xu, Ye Tian, Hai-Feng Yu, Dong-Ning Zheng, Heng Fan, Shi-Ping Zhao
Summary: The Loschmidt echo is a useful diagnostic tool for evaluating the perfection of quantum time-reversal processes and the sensitivity of quantum evolution to small perturbations. In this study, we measured the Loschmidt echo in a superconducting 10-qubit system using Floquet engineering and discussed the imperfection of initial Bell-state recovery caused by the next-nearest-neighbor (NNN) coupling in the qubit device. Our results demonstrate that the Loschmidt echo is highly sensitive to small perturbations during quantum-state evolution, which can be employed to investigate aspects such as many-body decoherence and entanglement in multiqubit systems.
Article
Physics, Multidisciplinary
Qingling Zhu, Zheng-Hang Sun, Ming Gong, Fusheng Chen, Yu-Ran Zhang, Yulin Wu, Yangsen Ye, Chen Zha, Shaowei Li, Shaojun Guo, Haoran Qian, He-Liang Huang, Jiale Yu, Hui Deng, Hao Rong, Jin Lin, Yu Xu, Lihua Sun, Cheng Guo, Na Li, Futian Liang, Cheng-Zhi Peng, Heng Fan, Xiaobo Zhu, Jian-Wei Pan
Summary: Understanding phenomena in nonequilibrium dynamics of closed quantum many-body systems is crucial. This study uses a ladder-type superconducting quantum processor to simulate different models and reveals quantum thermalization and information scrambling. The controllable qubit ladder shows ergodicity and scrambling.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Multidisciplinary
Kai Xu, Yu-Ran Zhang, Zheng-Hang Sun, Hekang Li, Pengtao Song, Zhongcheng Xiang, Kaixuan Huang, Hao Li, Yun-Hao Shi, Chi-Tong Chen, Xiaohui Song, Dongning Zheng, Franco Nori, H. Wang, Heng Fan
Summary: Multipartite entangled states are important resources for quantum information processing and quantum metrology. Non-Gaussian entangled states are predicted to achieve higher precision measurements than Gaussian states. In this study, a 19-qubit superconducting processor was used to characterize multiparticle entangled states generated during nonlinear dynamics. The linear Ramsey squeezing parameter (RSP) and nonlinear squeezing parameter (NLSP) were measured, and a large metrological gain over the standard quantum limit was observed, indicating a high level of multiparticle entanglement for quantum-enhanced phase sensitivity. The superconducting processor provides an ideal platform for engineering and benchmarking non-Gaussian entangled states.
PHYSICAL REVIEW LETTERS
(2022)
Editorial Material
Physics, Multidisciplinary
Ming-Liang Hu, Heng Fan
SCIENCE CHINA-PHYSICS MECHANICS & ASTRONOMY
(2022)
Article
Multidisciplinary Sciences
Tong Liu, Shang Liu, Hekang Li, Hao Li, Kaixuan Huang, Zhongcheng Xiang, Xiaohui Song, Kai Xu, Dongning Zheng, Heng Fan
Summary: The authors used a fully connected superconducting quantum processor with up to 15 qubits to confirm the interesting phenomenology of entanglement phase diagrams of Haar-measure random states, including entanglement phase transitions. Random quantum states are powerful tools in various scientific fields, and it has been theoretically predicted that entanglement transitions can occur for different partitions of multipartite random quantum states. This experimental study demonstrates entanglement transitions using negativity as the witness in a fully connected superconducting processor.
NATURE COMMUNICATIONS
(2023)
Article
Physics, Multidisciplinary
Wei-Bin Yan, Ying-Jie Zhang, Zhong-Xiao Man, Heng Fan, Yun-Jie Xia
Summary: A novel quantum-optics scheme for supervised learning is proposed based on the excellent control of single photons realized by atom-photon-chiral couplings. The single-photon rotating and phase-shift operations, which can be controlled by another single photon, are achieved by proper atom-photon-chiral couplings. Moreover, an algorithm is implemented to perform the supervised learning tasks by integrating the realized gates and adjusting the gate parameters.
ANNALEN DER PHYSIK
(2023)
Article
Physics, Multidisciplinary
Yun-Hao Shi, Yu Liu, Yu-Ran Zhang, Zhongcheng Xiang, Kaixuan Huang, Tao Liu, Yong-Yi Wang, Jia-Chi Zhang, Cheng-Lin Deng, Gui-Han Liang, Zheng-Yang Mei, Hao Li, Tian-Ming Li, Wei-Guo Ma, Hao-Tian Liu, Chi-Tong Chen, Tong Liu, Ye Tian, Xiaohui Song, Kai Xu, Dongning Zheng, Franco Nori, Heng Fan
Summary: This study develops a one-dimensional 43-qubit superconducting quantum processor called Chuang-tzu, which is used to simulate and characterize emergent topological states. The quantum processor is capable of capturing important topological features of quantum systems, providing a new method for studying quantum topological systems in the NISQ era.
PHYSICAL REVIEW LETTERS
(2023)
Article
Quantum Science & Technology
Wen Ning, Ri-Hua Zheng, Yan Xia, Kai Xu, Hekang Li, Dongning Zheng, Heng Fan, Fan Wu, Zhen-Biao Yang, Shi-Biao Zheng
Summary: This study reveals a more fundamental and universal interference behavior beyond Zitterbewegung in phase space for Dirac particles, which is confirmed by both numerical simulation and on-chip experiment. This discovery is of fundamental importance in science and holds potential applications in quantum technology.
NPJ QUANTUM INFORMATION
(2023)
Article
Optics
Li -Hang Ren, Yun-Hao Shi, Jin-Jun Chen, Heng Fan
Summary: We propose generalized state-dependent entropic uncertainty relations, obtaining the optimal lower bound by considering different measurement sequences. We apply this relation to detect entanglement, giving experimentally accessible lower bounds on both bipartite and tripartite entanglements. We demonstrate the detection of multipartite entanglement up to ten qubits using the QUAFU cloud quantum computation platform.
Article
Materials Science, Multidisciplinary
Shang-Shu Li, Rui-Zhen Huang, Heng Fan
Summary: We study the quantum thermalization and information scrambling dynamics of an experimentally realizable quantum spin model, which has homogeneous XX-type all-to-all interactions and random local potentials. By changing the disorder strength under a proper all-to-all interaction strength, we identify the transition from thermalization to localization. The scrambling dynamics in the localization phase shows different behaviors from local models, but the operator scrambling grows at almost the same rate in both phases. In the thermal phase, we show that fast scrambling can be observed without appealing to the semiclassical limit. We also briefly discuss the experimental realization of the model using superconducting qubit quantum simulators.
Article
Physics, Multidisciplinary
Zhan Wang, Zi-Yong Ge, Zhongcheng Xiang, Xiaohui Song, Rui-Zhen Huang, Pengtao Song, Xue-Yi Guo, Luhong Su, Kai Xu, Dongning Zheng, Heng Fan
Summary: The study experimentally investigates the emergence of Z(2) gauge invariance in a 1D superconducting circuit, demonstrating that despite the absence of gauge structure in the effective Hamiltonian, gauge invariance can still emerge in low-energy regimes.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Physics, Multidisciplinary
Yu-Ran Zhang, Yu Zeng, Tao Liu, Heng Fan, J. Q. You, Franco Nori
Summary: We demonstrate that multipartite entanglement witnessed by the quantum Fisher information can characterize topological quantum phase transitions in the spin-21 toric code model. We identify the topological order by its scaling behavior using the ground state's quantum Fisher information density. We also investigate the thermalization and disorder-assisted stabilization of topological order using the multipartite entanglement witness.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Optics
Tong Liu, Yu-Ran Zhang, Kai Xu, Jian Cui, Heng Fan
Summary: We propose a scheme for discrete time crystals (DTCs) based on the metastability of the driven-dissipative Bose-Hubbard model, linking the two metastable states using rotation operations and two-photon processes, and validate it through numerical analysis. The scheme only requires local dissipations and uniform rotations, making it feasible on current noisy intermediate-scale quantum platforms.
Article
Physics, Multidisciplinary
Zi-Yong Ge, Rui-Zhen Huang, Zi-Yang Meng, Heng Fan
Summary: This article proposes an implementation to approximately simulate DOUBLE-STRUCK CAPITAL Z(2) lattice gauge theory (LGT) on superconducting quantum circuits. It systematically investigates both the ground state properties and quench dynamics, shedding light on quantum phase transitions and confinement dynamics in LGT. The results pave the way for simulating LGT on superconducting circuits.
