arXiv subjects

Y. C. Wang

Publications and source records attributed to Y. C. Wang.

7 recordsLinked to original sources

arXiv2025

An Improved Quantum Algorithm of the Multislice Method

The multisilce method is an important algorithm for electron diffraction and image simulations in transmission electron microscopy. We have proposed a quantum algorithm of the multislice method based on quantum circuit model previously. In this work we have developed an improved quantum algorithm. We reconstruct the phase-shifting quantum circuit without using the multi-controlled quantum gates, thereby significantly improve the computation efficiency. The new quantum circuit also allows further gate count reduction at the cost of a controllable error. We have simulated the quantum circuit on a classical supercomputer and analyzed the result to prove the feasibility and correctness of the improved quantum algorithm. We also provide proper parameter settings through testing, allowing the minimization of the necessary number of quantum gates while limiting the relative error within 1%. This work demonstrates the potential of applying quantum computing to electron diffraction simulations and achieving quantum advantages.

quant-ph↗

arXiv2024

A 0.96pJ/SOP, 30.23K-neuron/mm^2 Heterogeneous Neuromorphic Chip With Fullerene-like Interconnection Topology for Edge-AI Computing

Edge-AI computing requires high energy efficiency, low power consumption, and relatively high flexibility and compact area, challenging the AI-chip design. This work presents a 0.96 pJ/SOP heterogeneous neuromorphic system-on-chip (SoC) with fullerene-like interconnection topology for edge-AI computing. The neuromorphic core integrates different technologies to augment computing energy efficiency, including sparse computing, partial membrane potential updates, and non-uniform weight quantization. Multiple neuromorphic cores and multi-mode routers form a fullerene-like network-on-chip (NoC). The average degree of communication nodes exceeds traditional topologies by 32%, with a minimal degree variance of 0.93, allowing advanced decentralized on-chip communication. Additionally, the NoC can be scaled up through extended off-chip high-level router nodes. A RISC-V CPU and a neuromorphic processor are tightly coupled and fabricated within a 5.42 mm^2 die area under 55 nm CMOS technology. The chip has a low power density of 0.52 mW/mm^2, reducing 67.5% compared to related works, and achieves a high neuron density of 30.23 K/mm^2. Eventually, the chip is demonstrated to be effective on different datasets and achieves 0.96 pJ/SOP energy efficiency.

cs.AR↗

arXiv2021

First experimental constraints on WIMP couplings in the effective field theory framework from CDEX

We present weakly interacting massive particles (WIMPs) search results performed using two approaches of effective field theory from the China Dark Matter Experiment (CDEX), based on the data from both CDEX-1B and CDEX-10 stages. In the nonrelativistic effective field theory approach, both time-integrated and annual modulation analyses were used to set new limits for the coupling of WIMP-nucleon effective operators at 90% confidence level (C.L.) and improve over the current bounds in the low $m_χ$ region. In the chiral effective field theory approach, data from CDEX-10 were used to set an upper limit on WIMP-pion coupling at 90% C.L. We for the first time extended the limit to the $m_χ<$ 6 GeV/$c^2$ region.

hep-ex↗

arXiv2020

Connection between Bandgap Evolution and Strains of Octahedron in non-Perovskite \b{eta}-MnO2 under pressure: A First Principle Study

Lattice distortion due to octahedral rotation and distortion are high focussed, and it produces profound effect on a material's properties, such as its bandgap, magnetism and optical properties etc. Rutile-type \b{eta}-MnO2 is a wide used non-Perovskite magnetic material with octahedrons. We systematically studied its stability, electronic structures, magnetic structures, and optical properties within 0-100 GPa with density-functional theory (DFT). We find that the competition between bondlength and bonding angle leads its bandgap enlarging or shrinking within in the Pnnm phase with increasing pressure, because of the interaction of Mn-d and O-p states. We also find same pressure indused bandgap evolutions in the Pnnm phases of SiO2, GeO2, SnO2 and PbO2. The different ways of octahedral connection in Pnnm phase and Pa-3 phase leads to an interesting pressure-induced bandgap enlarging. And in the Pa-3 phase, the band gap can be tuned to 1.34 eV by pressure to meet the Shockley-Queisser limit. Moreover the two high pressure phases can be quenched to ambient pressure. Together with its mechanical, optical and antiferromagnetic properties, it ensures MnO2's application as a photovoltaic material for all working condition with multi-purpose. This study extends MnO2's application and give some new mechanism of pressure induced bandgap enlargement.

cond-mat.mtrl-sci↗

arXiv2020

A Large Effective Phonon Magnetic Moment in a Dirac Semimetal

We investigated the magnetoterahertz response of the Dirac semimetal Cd$_3$As$_2$ and observed a particularly low frequency optical phonon, as well as a very prominent and field sensitive cyclotron resonance. As the cyclotron frequency is tuned with field to pass through the phonon, the phonon become circularly polarized as shown by a notable splitting in their response to right- and left-hand polarized light. This splitting can be expressed as an effective phonon magnetic moment that is approximately 2.7 times the Bohr magneton, which is almost four orders of magnitude larger than ab initio calculations predict for phonon magnetic moments in nonmagnetic insulators. This exceedingly large value is due to the coupling of the phonons to the cyclotron motion and is controlled directly by the electron-phonon coupling constant. This field tunable circular-polarization selective coupling provides new functionality for nonlinear optics to create light-induced topological phases in Dirac semimetals.

cond-mat.mes-hall↗

arXiv1998

dbar/ubar Asymmetry and the Origin of the Nucleon Sea

The Drell-Yan cross section ratios, $σ(p+d)/σ(p+p)$, measured in Fermilab E866, have led to the first determination of $\bar d(x) / \bar u(x)$, $\bar d(x) - \bar u(x)$, and the integral of $\bar d(x) - \bar u(x)$ for the proton over the range $0.02 \le x \le 0.345$. The E866 results are compared with predictions based on parton distribution functions and various theoretical models. The relationship between the E866 results and the NMC measurement of the Gottfried integral is discussed. The agreement between the E866 results and models employing virtual mesons indicates these non-perturbative processes play an important role in the origin of the $\bar d$, $\bar u$ asymmetry in the nucleon sea.

hep-ph↗

arXiv1998

Measurement of the Light Antiquark Flavor Asymmetry in the Nucleon Sea

A precise measurement of the ratio of Drell-Yan yields from an 800 GeV/c proton beam incident on hydrogen and deuterium targets is reported. Over 140,000 Drell-Yan muon pairs with dimuon mass M_{mu+ mu-} >= 4.5 GeV/c^2 were recorded. From these data, the ratio of anti-down (dbar) to anti-up (ubar) quark distributions in the proton sea is determined over a wide range in Bjorken-x. A strong x dependence is observed in the ratio dbar/ubar, showing substantial enhancement of dbar with respect to ubar for x<0.2. This result is in fair agreement with recent parton distribution parameterizations of the sea. For x>0.2, the observed dbar/ubar ratio is much nearer unity than given by the parameterizations.

hep-ex↗