arXiv subjects

Zhiying Chen

Publications and source records attributed to Zhiying Chen.

6 recordsLinked to original sources

arXiv2026

Refractive Index Dispersion Fingerprinting via Scanning-Free Parallel Multi-Wavelength SPR on a Single Aluminum Film

Real-time characterization of refractive index (RI) dispersion is pivotal for advanced optical sensing, yet conventional surface plasmon resonance (SPR) platforms are bottlenecked by the narrow bandwidth of noble metals (Au, Ag) and the mechanical instability of sequential scanning. Here, we report a novel Al-based parallel SPR platform that overcomes the bandwidth and temporal constraints of conventional noble-metal systems. Leveraging the unique low-loss broadband response of Al, enabled by the suppression of interband transitions, we engineered a system for simultaneous excitation at 450, 520, and 635 nm. By integrating spectral-angle multiplexing with RGB-channel demultiplexing on a CMOS camera, the platform achieved acquisition of dispersion profiles without mechanical motion. Validated against NaCl solutions, the system demonstrates metrological accuracy and exceptional agreement with Cauchy dispersion models. The proposed architecture eliminates temporal drift and vibration errors, establishing a new benchmark for real-time dispersion characterization. By decoupling sensing from mechanical constraints, this work pioneers a compact, robust framework for next-generation, field-deployable sensors capable of distinguishing complex analytes via their unique spectral signatures.

physics.optics↗

arXiv2026

A Field-Weighted model for Surface Layer Characterization using Single Channel Intensity Interrogation SPR

To address the difficulty of characterizing the surface layer rigorously, especially the thickness and refractive index (RI) in surface plasmon resonance (SPR) technology, we propose a field-weighted analysis method. This approach enables simultaneous quantitative determination of RI for the bulk solution and the surface layer. This study utilizes the aluminum-based Kretschmann structure with the intensity interrogation technique. We construct the field-weighted model governed by the evanescent field penetration depth to decompose the SPR reflected intensity into the bulk and surface responses. Experiments are conducted using bovine serum albumin (BSA) solution to form a surface adsorbed protein layer, and different concentrations of BSA are tested. Results show that the separated surface response fits well with the Langmuir formula, representing a significant improvement over the untreated SPR signal. The bulk and surface responses are then incorporated into the field-weighted model to determine the RI values of the bulk BSA solution and the surface adsorbed BSA layer at various concentrations. The experimental results of BSA solution match the Abbe refractometer measurements with a maximum error 0.0004 in RI, while the results of the adsorbed BSA layer, both the RI and thickness, aligned well with reported parameters for a single BSA layer. This method eliminates the stage rotation in the common angular interrogation SPR technique and complicated optical design and nano-fabrication in the nano-optics sensing schemes, making it suitable for compact, low-cost SPR platforms for practical applications needing surface layer characterization.

physics.optics↗

arXiv2014

High-T_c superconductivity in ultrathin Bi_2Sr_2CaCu_2O_8+x down to halfunit-cell thickness by protection with graphene

High-T_c superconductors confined to two dimension exhibit novel physical phenomena, such as superconductor-insulator transition. In the Bi_2Sr_2CaCu_2O_8+x (Bi2212) model system, despite extensive studies, the intrinsic superconducting properties at the thinness limit have been difficult to determine. Here we report a method to fabricate high quality single-crystal Bi2212 films down to half-unit-cell thickness in the form of graphene/Bi2212 van der Waals heterostructure, in which sharp superconducting transitions are observed. The heterostructure also exhibits a nonlinear current-voltage characteristic due to the Dirac nature of the graphene band structure. More interestingly, although the critical temperature remains essentially the same with reduced thickness of Bi2212, the slope of the normal state T-linear resistivity varies by a factor of 4-5, and the sheet resistance increases by three orders of magnitude, indicating a surprising decoupling of the normal state resistance and superconductivity. The developed technique is versatile, applicable to investigate other two-dimensional (2D) superconducting materials.

cond-mat.supr-con↗

arXiv2004

Simulation of the Burgers equation by NMR quantum information processing

We report on the implementation of Burgers equation as a type-II quantum computation on an NMR quantum information processor. Since the flow field evolving under the Burgers equation develops sharp features over time, this is a better test of liquid state NMR implementations of type-II quantum computers than the previous examples using the diffusion equation. In particular, we show that Fourier approximations used in the encoding step are not the dominant error. Small systematic errors in the collision operator accumulate and swamp all other errors. We propose, and demonstrate, that the accumulation of this error can be avoided to a large extent by replacing the single collision operator with a set of operators with random errors and similar fidelities. Experiments have been implemented on 16 two-qubit sites for eight successive time steps for the Burgers equation.

quant-ph↗

arXiv2004

NMR Quantum Information Processing

Nuclear Magnetic Resonance (NMR) has provided a valuable experimental testbed for quantum information processing (QIP). Here, we briefly review the use of nuclear spins as qubits, and discuss the current status of NMR-QIP. Advances in the techniques available for control are described along with the various implementations of quantum algorithms and quantum simulations that have been performed using NMR. The recent application of NMR control techniques to other quantum computing systems are reviewed before concluding with a description of the efforts currently underway to transition to solid state NMR systems that hold promise for scalable architectures.

quant-ph↗

arXiv2003

Experimental Demonstration of Quantum Lattice Gas Computation

We report an ensemble nuclear magnetic resonance (NMR) implementation of a quantum lattice gas algorithm for the diffusion equation. The algorithm employs an array of quantum information processors sharing classical information, a novel architecture referred to as a type-II quantum computer. This concrete implementation provides a test example from which to probe the strengths and limitations of this new computation paradigm. The NMR experiment consists of encoding a mass density onto an array of 16 two-qubit quantum information processors and then following the computation through 7 time steps of the algorithm. The results show good agreement with the analytic solution for diffusive dynamics. We also describe numerical simulations of the NMR implementation. The simulations aid in determining sources of experimental errors, and they help define the limits of the implementation.

quant-ph↗