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Pengcheng Lu

Publications and source records attributed to Pengcheng Lu.

13 recordsLinked to original sources

Skyrmion Quantum Diode Prototype: Bridging Micromagnetic Simulations and Quantum Models

Magnetic skyrmions are topologically protected spin textures known for their robustness against perturbations. Their topological stability makes them robust information carriers, ideal for tackling a key challenge in quantum computing: creating reliable, one-way links between different types of qubits. In this proof-of-concept study, we introduce a novel device - the skyrmion quantum diode - based on skyrmion qubits. Our approach combines classical micromagnetic simulations, achieving skyrmion diameters as small as 3 nm, with quantum circuit models inspired by superconducting qubits. In this work, we demonstrate: (i) unidirectional skyrmion transport via the skyrmion Hall effect in asymmetric junctions, spanning length scales from 20 nm down to 3 nm; (ii) potential compatibility with flux-tunable quantum architectures; and (iii) preliminary insights into anharmonicity in skyrmion-based qubit systems. These results establish both the operational feasibility and the scaling behavior necessary for a hybrid skyrmion-quantum platform. Our work outlines a path toward integrating skyrmion based quantum components into practical device architectures, enabling low-dissipation, unidirectional quantum information transport. This capability is crucial for scalable quantum computing, spintronic logic, and hybrid quantum systems, and opens opportunities for chipscale, pump-free isolators and directional quantum links that enhance readout fidelity, reduce cryogenic load, and support modular skyrmion-superconducting processors

quant-ph

Exact physical quantities of the $D_2^{(2)}$ spin chain model with generic open boundary conditions

We study the quantum integrable spin chain model associated with the twisted $D_2^{(2)}$ algebra (or simply the $D_2^{(2)}$ model) under generic open boundary conditions. The Hamiltonian of this model can be factorized into the sum of two staggered XXZ spin chains. Applying the $t$-$W$ method, we derive the homogeneous Bethe ansatz equations for the zeros of the transfer matrix eigenvalues and the patterns of the corresponding zeros of the staggered XXZ spin chain with generic integrable boundaries. Based on these results, we analytically compute the surface energies and excitation energies of the $D_2^{(2)}$ model in different regimes of boundary parameters.

math-ph

Exact surface energies and boundary excitations of the Izergin-Korepin model with generic boundary fields

The Izergin-Korepin model is an integrable model with the simplest twisted quantum affine algebra $U_q(A_2^{(2)})$ symmetry. Applying the $t-W$ method, we derive the homogeneous zero roots Bethe ansatz equations and the corresponding zero root patterns of the Izergin-Korepin model with generic integrable boundaries. Based on these results, we analytically compute the surface energies and boundary excitations in different regimes of boundary parameters of the model. It is shown that in some regimes, correlation effect appears between two boundary fields.

math-ph

Integrating 2D Magnets for Quantum Devices: from Materials and Characterization to Future Technology

The unveiling of 2D van der Waals magnetism in 2017 ignited a surge of interest in low-dimensional magnetism. With dimensions reduced, research has delved into facile electric control of 2D magnetism, high-quality heterostructure design, and new device functionality. These atomically thin magnetic materials have spawned a burgeoning field known as 2D spintronics, holding immense promise for future quantum technologies. In this review, we comprehensively survey the current advancements in 2D magnet-based quantum devices, accentuating their role in manifesting exotic properties and enabling novel functionalities. Topological states, spin torques, voltage control of magnetic anisotropy, strain engineering, twistronics and designer interface will be discussed. Furthermore, we offer an outlook to guide their development in future CMOS and quantum hardware paradigms.

cond-mat.mes-hall

Integrating knowledge bases to improve coreference and bridging resolution for the chemical domain

Resolving coreference and bridging relations in chemical patents is important for better understanding the precise chemical process, where chemical domain knowledge is very critical. We proposed an approach incorporating external knowledge into a multi-task learning model for both coreference and bridging resolution in the chemical domain. The results show that integrating external knowledge can benefit both chemical coreference and bridging resolution.

cs.CL

T-W relation and free energy of the antiperiodic XXZ chain with {\eta}=i{\pi}/3 at a finite temperature

We study the thermodynamics of the antiperiodic XXZ chain with anisotropy parameter {\eta}=i{\pi}/3 by means of the t-W method. We parameterize the eigenvalues of both the transfer matrix and the corresponding fused transfer matrix by their zero points instead of Bethe roots. Based on the patterns of the zero points distribution and the reconstructed entropy, we obtain the nonlinear integral equations (NLIEs) describing the thermodynamics of the model and compute its free energy at a finite temperature.

cond-mat.stat-mech

Root patterns and exact surface energy of the spin-1 Heisenberg model with generic open boundaries

We investigate the thermodynamic limit and exact surface energy of the isotropic spin-1 Heisenberg chain with integrable generic open boundary conditions by a novel Bethe ansatz method. We obtain the homogeneous Bethe ansatz equations for the zero roots of the transfer matrix. Based on the patterns of the zero roots, we analytical calculate the densities of zero roots and the surface energies of the model in all regimes of the boundary parameters.

math-ph

2D Magnetic Heterostructures: Spintronics and Quantum Future

The discovery of two-dimensional (2D) magnetism within atomically thin structures derived from layered crystals has opened up a new realm for exploring magnetic heterostructures. This emerging field provides a foundational platform for investigating unique physical properties and exquisite phenomena at the nanometer and molecular/atomic scales. By engineering 2D interfaces using physical methods and selecting interlayer interactions, we unlock the potential for extraordinary exchange dynamics. This potential extends to high-performance and high-density magnetic memory applications, as well as future advancements in neuromorphic and quantum computing. This review delves into recent advances in 2D magnets, elucidates the mechanisms behind 2D interfaces, and highlights the development of 2D devices for spintronics and quantum information. Particular focus is placed on 2D magnetic heterostructures with topological properties, promising for a resilient and low-error information system. Finally, we discuss the trends of 2D heterostructures for future electronics, considering the challenges and opportunities from physics, material synthesis, and technological prospective.

cond-mat.mes-hall

SourceP: Detecting Ponzi Schemes on Ethereum with Source Code

As blockchain technology becomes more and more popular, a typical financial scam, the Ponzi scheme, has also emerged in the blockchain platform Ethereum. This Ponzi scheme deployed through smart contracts, also known as the smart Ponzi scheme, has caused a lot of economic losses and negative impacts. Existing methods for detecting smart Ponzi schemes on Ethereum mainly rely on bytecode features, opcode features, account features, and transaction behavior features of smart contracts, which are unable to truly characterize the behavioral features of Ponzi schemes, and thus generally perform poorly in terms of detection accuracy and false alarm rates. In this paper, we propose SourceP, a method to detect smart Ponzi schemes on the Ethereum platform using pre-trained models and data flow, which only requires using the source code of smart contracts as features. SourceP reduces the difficulty of data acquisition and feature extraction of existing detection methods. Specifically, we first convert the source code of a smart contract into a data flow graph and then introduce a pre-trained model based on learning code representations to build a classification model to identify Ponzi schemes in smart contracts. The experimental results show that SourceP achieves 87.2% recall and 90.7% F-score for detecting smart Ponzi schemes within Ethereum's smart contract dataset, outperforming state-of-the-art methods in terms of performance and sustainability. We also demonstrate through additional experiments that pre-trained models and data flow play an important contribution to SourceP, as well as proving that SourceP has a good generalization ability.

cs.SE

Exact physical quantities of a competing spin chain in the thermodynamic limit

We study the exact physical quantities of a competing spin chain which contains many interesting and meaningful couplings including the nearest neighbor, next nearest neighbor, chiral three spins, Dzyloshinsky-Moriya interactions and unparallel boundary magnetic fields in the thermodynamic limit. We obtain the density of zero roots, surface energies and elementary excitations in different regimes of model parameters. Due to the competition of various interactions, the surface energy and excited spectrum show many different pictures from those of the Heisenberg spin chain.

math-ph

Coreference Resolution for the Biomedical Domain: A Survey

Issues with coreference resolution are one of the most frequently mentioned challenges for information extraction from the biomedical literature. Thus, the biomedical genre has long been the second most researched genre for coreference resolution after the news domain, and the subject of a great deal of research for NLP in general. In recent years this interest has grown enormously leading to the development of a number of substantial datasets, of domain-specific contextual language models, and of several architectures. In this paper we review the state-of-the-art of coreference in the biomedical domain with a particular attention on these most recent developments.

cs.CL

T-W relation and free energy of the Heisenberg chain at a finite temperature

A new nonlinear integral equation (NLIE) describing the thermodynamics of the Heisenberg spin chain is derived based on the t-W relation of the quantum transfer matrices. The free energy of the system in a magnetic field is thus obtained by solving the NLIE. This method can be generalized to other lattice quantum integrable models. Taking the SU(3)-invariant quantum spin chain as an example, we construct the corresponding NLIEs and compute the free energy. The present results coincide exactly with those obtained via other methods previously.

math-ph

Coherence of an extended central spin model with a coupled spin bath

We study an extended central spin model with an isotropic nearest-neighbour spin-exchange interaction among the bath spins. The system is controllable by external magnetic fields applied on the central spin and the bath, respectively. We construct a basis set of the Hilbert space and express the Hamiltonian of the extended model into a series of $2\times2$ block matrices to obtain the exact solution of the model successfully. Therefrom, the coherence and the spin polarization of the central spin are investigated. We find that if the couplings among the bath spins are antiferromagnetic, the central spin has good coherence and polarization at low temperatures. Moreover, the decoherence is greatly suppressed at the critical point where the strengthes of the central and the bath magnetic field take the same value. A dephasing phenomenon is identified when the initial state of the central spin is unpolarized.

cond-mat.str-el