Article
Physics, Multidisciplinary
Simon Morelli, Hayata Yamasaki, Marcus Huber, Armin Tavakoli
Summary: This study investigates entanglement detection in scenarios where local measurements only nearly correspond to the intended measurements. The authors formalize this through an operational notion of inaccuracy that can be estimated directly in the lab. They demonstrate that small magnitudes of inaccuracy can significantly compromise well-known entanglement witnesses.
PHYSICAL REVIEW LETTERS
(2022)
Article
Optics
Jiru Liu, Yusef Maleki, M. Suhail Zubairy
Summary: This paper discusses a protocol for enhancing entanglement in a two-mode squeezed vacuum state using photon subtraction, photon catalysis, and photon addition. It focuses on the task of mixing and detecting number states in each mode to improve the entanglement of the state.
Article
Physics, Multidisciplinary
Yibin Zhang, Peiyu Wang, Mei Zhang, Junzhong Yang
Summary: In this study, heterogeneity is introduced into a ring of nonlocally coupled bicomponent FitzHugh-Nagumo oscillators by randomly partitioning oscillators into two groups with different epsilon values. It is found that a synchronous chimera state appears at weak mismatch between epsilon values, while an asynchronous chimera state emerges at strong mismatch, which is not sensitive to the partition of oscillators. The existence of an asynchronous chimera state at strong mismatch of epsilon contradicts the common view that strong heterogeneity in non-identical oscillators is harmful to the chimera state.
Article
Physics, Multidisciplinary
R. L. Willett, K. Shtengel, C. Nayak, L. N. Pfeiffer, Y. J. Chung, M. L. Peabody, K. W. Baldwin, K. W. West
Summary: In this study, we provide experimental evidence for the non-Abelian nature of excitations at v = 7/2 by measuring resistance oscillations in Fabry-Pérot interferometers using new high-purity heterostructures. We also examine the fermion parity of non-Abelian quasiparticles at both v = 5/2 and v = 7/2 for the first time. These findings support the utility of e/4 quasiparticles for topological quantum computation.
Article
Multidisciplinary Sciences
Armin Tavakoli, Mate Farkas, Denis Rosset, Jean-Daniel Bancal, Jedrzej Kaniewski
Summary: The text discusses the importance of mutually unbiased bases (MUBs) and symmetric informationally complete projectors (SICs) in quantum theory, particularly in the context of quantum nonlocality. It highlights the development of Bell inequalities, device-independent certification, and protocols for quantum key distribution and quantum random number generation using MUBs and SICs. Additionally, it presents the first example of an extremal point in the quantum set of correlations with physically inequivalent quantum realizations.
Article
Mathematics, Applied
L. Messee Goulefack, Marlon F. Ramos, R. Yamapi, C. Anteneodo
Summary: In this study, the dynamics of nonlocally coupled Hindmarsh-Rose neurons modified by coupling the induced magnetic flux to the membrane potential with a quadratic memristor of strength k were investigated. The nonlocal coupling involved the interaction of each neuron with its neighbors within a fixed radius, influencing the membrane potential with coupling intensity sigma. The study examined how variations of k and sigma affect the collective dynamics, finding that coherence typically increased when k and sigma were increased, except for small parameter ranges where the opposite behavior could occur. Moreover, varying k also affected the pattern of bursts and spikes, resulting in an increase in burst frequency, a decrease in the number and amplitude of spikes, and longer quiescent periods.
Article
Quantum Science & Technology
Luca Gravina, Fabrizio Minganti, Vincenzo Savona
Summary: Encoding quantum information onto bosonic systems is a promising route to quantum error correction. Different encoding schemes, such as cat codes and Kerr-cat qubits, have been proposed and investigated. In this study, a critical cat code is proposed, which combines two-photon loss and Kerr nonlinearity and allows for detuning of the two-photon drive. The performance of this code is evaluated and it is found that large detunings and small two-photon loss rates are crucial for optimal performance. Additionally, a dissipative phase transition and a protocol for initializing the system are discussed. The critical cat code shows resilience to random frequency shifts, making it a reliable option for scalable and concatenated bosonic qubit architectures.
Article
Physics, Fluids & Plasmas
Chol-Ung Choe, Myong-Su Ho, Ryong-Son Kim
Summary: This study reports on an asymmetric spiral chimera with nonidentical incoherent cores of different sizes on the spherical surface of identical phase oscillators with nonlocal coupling. The bifurcation conditions of asymmetric spiral chimeras are derived and it is revealed that the asymmetric spiral chimera state emerges from the symmetric spiral chimera via a supercritical symmetry-breaking bifurcation. Rigorous stability analyses are carried out for different types of spiral chimeras and the complete stability diagram is presented. The theoretical findings are verified through extensive numerical simulations.
Article
Optics
Kaelan Donatella, Zakari Denis, Alexandre Le Boite, Cristiano Ciuti
Summary: Despite the challenges posed by stochastic noise and regularization hyperparameters, a new alternative scheme utilizing a normalized neural-network ansatz enables the reliable capture of long-time dynamics in complex quantum systems. Applying this scheme to the two-dimensional quantum Ising model, we observe excellent agreement with exact dynamics and recover scaling laws consistent with other variational methods.
Article
Engineering, Mechanical
Mingxue Yang, Shuangjian Guo, Yirui Chen, Qionglin Dai, Haihong Li, Junzhong Yang
Summary: This study identified a two-frequency chimera state in which oscillators in different coherent domains oscillate at different velocities. Oscillators in coherent domains with higher mean phase velocity almost synchronize, while those in domains with lower mean phase velocity are randomly partitioned into two groups in antiphase. Additionally, the dynamics of local mean fields in these two types of coherent domains are found to be different.
NONLINEAR DYNAMICS
(2021)
Article
Optics
Gaoyan Zhu, Chengjie Zhang, Kunkun Wang, Lei Xiao, Peng Xue
Summary: We experimentally demonstrate a method for detecting entanglement using a limited set of local measurements. The method does not require prior knowledge about the form of entanglement witnesses and has been successfully applied to both pure and mixed two-qubit entangled states. The results show the validity of the method and provide a practical test bed for entanglement witness experiments.
PHOTONICS RESEARCH
(2022)
Article
Chemistry, Multidisciplinary
Razmik A. Hovhannisyan, Olena M. Kapran, Taras Golod, Vladimir M. Krasnov
Summary: In this research, it is demonstrated theoretically and experimentally that the Josephson critical current Ic can be accurately extracted using first and third harmonic lock-in measurements of junction resistance. Analytical expressions were derived and experimentally verified on nano-scale Nb-PtNi-Nb and Nb-CuNi-Nb Josephson junctions.
Article
Mathematics, Applied
Elena Rybalova, Galina Strelkova
Summary: In this study, we numerically investigate the impact of heterogeneity in parameters on the dynamics of nonlocally coupled discrete-time systems. We explore the robustness of solitary states, which occur during the transition from coherence to incoherence, to heterogeneity in local dynamics or coupling strength. The results show that solitary states are suppressed when network parameters are modulated by noise, but they can persist in the case of static randomly distributed system parameters.
Article
Optics
Wen -Long Ma, Shu-Shen Li, Ren-Bao Liu
Summary: This paper investigates the relationship between projective measurements and generalized quantum measurements, and provides a proof that projective measurements can be constructed from sequential generalized measurements under certain conditions. The paper also proposes a specific scheme for constructing projective measurements of a quantum system using sequential generalized measurements, and shows that a single ancilla qubit is sufficient for mediating sequential generalized measurements to construct arbitrary projective measurements.
Article
Quantum Science & Technology
Samuel Nolan, Augusto Smerzi, Luca Pezze
Summary: This theoretical study introduces a new method for Bayesian estimation using artificial neural networks, which shows superior performance with limited calibration data and is suitable for black-box sensors without explicit fitting models.
NPJ QUANTUM INFORMATION
(2021)