arXiv subjects

Qi Huang

Publications and source records attributed to Qi Huang.

At least 91 records · Page 5Linked to original sources

arXiv2023

System-Level Metrics for Non-Terrestrial Networks Under Stochastic Geometry Framework

Non-terrestrial networks (NTNs) are considered one of the key enablers in sixth-generation (6G) wireless networks; and with their rapid growth, system-level metrics analysis adds crucial understanding into NTN system performance. Applying stochastic geometry (SG) as a system-level analysis tool in the context of NTN offers novel insights into the network tradeoffs. In this paper, we study and highlight NTN common system-level metrics from three perspectives: NTN platform types, typical communication issues, and application scenarios. In addition to summarizing existing research, we study the best-suited SG models for different platforms and system-level metrics which have not been well studied in the literature. In addition, we showcase NTN-dominated prospective application scenarios. Finally, we carry out a performance analysis of system-level metrics for these applications based on SG models.

cs.NI↗

arXiv2023

Overlapped grouping measurement: A unified framework for measuring quantum states

Quantum algorithms designed for realistic quantum many-body systems, such as chemistry and materials, usually require a large number of measurements of the Hamiltonian. Exploiting different ideas, such as {importance sampling,} observable compatibility, or classical shadows of quantum states, different advanced measurement schemes have been proposed to greatly reduce the large measurement cost. Yet, the underline cost reduction mechanisms seem distinct from each other, and how to systematically find the optimal scheme remains a critical challenge. Here, we address this challenge by proposing a unified framework of quantum measurements, incorporating advanced measurement methods as special cases. Our framework allows us to introduce a general scheme~ -- ~overlapped grouping measurement, which simultaneously exploits the advantages of most existing methods. An intuitive understanding of the scheme is to partition the measurements into overlapped groups with each one consisting of compatible measurements. We provide explicit grouping strategies and numerically verify its performance for different molecular Hamiltonians with up to 16 qubits. Our numerical result shows significant improvements over existing schemes. Our work paves the way for efficient quantum measurement and fast quantum processing with current and near-term quantum devices.

quant-ph↗

arXiv2023

Probing quantum many-body correlations by universal ramping dynamics

Ramping a physical parameter is one of the most common experimental protocols in studying a quantum system, and ramping dynamics has been widely used in preparing a quantum state and probing physical properties. Here, we present a novel method of probing quantum many-body correlation by ramping dynamics. We ramp a Hamiltonian parameter to the same target value from different initial values and with different velocities, and we show that the first-order correction on the finite ramping velocity is universal and path-independent, revealing a novel quantum many-body correlation function of the equilibrium phases at the target values. We term this method as the non-adiabatic linear response since this is the leading order correction beyond the adiabatic limit. We demonstrate this method experimentally by studying the Bose-Hubbard model with ultracold atoms in three-dimensional optical lattices. Unlike the conventional linear response that reveals whether the quasi-particle dispersion of a quantum phase is gapped or gapless, this probe is more sensitive to whether the quasi-particle lifetime is long enough such that the quantum phase possesses a well-defined quasi-particle description. In the Bose-Hubbard model, this non-adiabatic linear response is significant in the quantum critical regime where well-defined quasi-particles are absent. And in contrast, this response is vanishingly small in both superfluid and Mott insulators which possess well-defined quasi-particles. Because our proposal uses the most common experimental protocol, we envision that our method can find broad applications in probing various quantum systems.

cond-mat.quant-gas↗

arXiv2022

Multi-surrogate Assisted Efficient Global Optimization for Discrete Problems

Decades of progress in simulation-based surrogate-assisted optimization and unprecedented growth in computational power have enabled researchers and practitioners to optimize previously intractable complex engineering problems. This paper investigates the possible benefit of a concurrent utilization of multiple simulation-based surrogate models to solve complex discrete optimization problems. To fulfill this, the so-called Self-Adaptive Multi-surrogate Assisted Efficient Global Optimization algorithm (SAMA-DiEGO), which features a two-stage online model management strategy, is proposed and further benchmarked on fifteen binary-encoded combinatorial and fifteen ordinal problems against several state-of-the-art non-surrogate or single surrogate assisted optimization algorithms. Our findings indicate that SAMA-DiEGO can rapidly converge to better solutions on a majority of the test problems, which shows the feasibility and advantage of using multiple surrogate models in optimizing discrete problems.

cs.NE↗

arXiv2022

Mixed Leadership Stochastic Differential Game in Feedback Information Pattern with Applications

This paper is devoted to a high-dimensional mixed leadership stochastic differential game on a finite horizon in feedback information mode, where the control variables enter into the diffusion term of state equation. A verification theorem for the feedback Stackelberg-Nash equilibrium is obtained by using a system of coupled and fully nonlinear parabolic partial differential equations. We apply the verification theorem to deal with a dynamic innovation and pricing decision problem where the buyer acts as the leader in the pricing decisions and the dynamic model is stochastic. Via the solutions of coupled Riccati equations, we explicitly express the feedback equilibrium strategies of innovation and pricing. And by analysis, the local existence and uniqueness of the solutions of the coupled Riccati equations is derived. We also conduct some numerical analyses to discuss the effects of model parameters on the feedback equilibrium strategies.

math.OC↗

arXiv2022

From the isovector molecular explanation of the newly $T_{c\bar{s}}^{a0(++)}(2900)$ to possible charmed-strange molecular pentaquarks

In this work, we adopt the one-boson-exchange model to study the $D^{(*)}K^{(*)}$ interactions. With the same parameters, we can simultaneously reproduce the masses of the $D_{s0}(2317)$, $D_{s1}(2460)$, and $T_{c\bar{s}}^{a0(++)}(2900)$ recently observed by the LHCb collaboration in the hadronic molecular picture, where the $D_{s0}(2317)$, $D_{s1}(2460)$, and $T_{c\bar{s}}^{a0(++)}(2900)$ are regarded as the $DK[I(J^P)=0(0^+)]$, $D^*K[0(1^+)]$, and $D^*K^*[1(0^+)]$ charmed-strange molecular states, respectively. In addition, we extend to study the $Λ_cK^{(*)}$ and $Σ_cK^{(*)}$ interactions and predict two possible charmed-strange molecular pentaquarks, the single $Σ_cK^*$ state with $I(J^P)=1/2(1/2^-)$ and $3/2(3/2^-)$. After considering the coupled channel effects, our results show that the coupled $Λ_cK^*/Σ_cK^*$ molecular state with $I(J^P)=1/2(1/2^-)$ and the coupled $Σ_cK/Λ_cK^*$ molecular state with $I(J^P)=1/2(1/2^-)$ can be good hadronic molecular candidates, the $Λ_cK^*({}^2S_{1/2})$ and $Σ_cK({}^2S_{1/2})$ are the dominant channels, respectively.

hep-ph↗

arXiv2022

Predicted $Λ\barΛ$ and $Ξ^-\barΞ^+$ decay modes of the charmoniumlike $Y(4230)$

In this work, we predict the light hadronic decay channels $Y(4230)\toΛ\barΛ$ and $Ξ^-\barΞ^+$ when treating the $Y(4230)$ as a vector charmonium state. By the hadronic loop mechanism, the branching ratios of the $Y(4230)\toΛ\barΛ$ and $Ξ^-\barΞ^+$ processes are calculated. In addition, we discuss the possibility of carrying out the search for the signal of the $Y(4230)$ through $Λ\barΛ$ and $Ξ^-\barΞ^+$ channels from the $e^+e^-$ annihilation. Assuming $Y(4230)$ exist in $Λ\barΛ$ and $Ξ^-\barΞ^+$ channel, we also present the time-like electromagnetic form factors (EMFFs) at $\sqrt{s}=m_{Y(4230)}$.

hep-ph↗

arXiv2022

$\mathbf{Υ(10753)\toΥ(nS)π^+π^-}$ decays induced by hadronic loop mechanism

In this work, we investigate the $Υ(10753)\toΥ(nS)π^+π^-$ ($n=1,2,3$) processes by considering the hadronic loop mechanism, where $Υ(10753)$ is assigned to a conventional bottomonium in the $4S$-$3D$ mixing scheme. Our results of the concerned processes own considerable branching ratios, which can reach up to the order of magnitude of $10^{-4}-10^{-3}$. We should indicate that the measured $Γ_{e^+e^-}\times\mathcal{B}[Υ(10753)\toΥ(nS)π^+π^-]$ values given by Belle can be reproduced well. This fact supports the former bottomonium assignment to the $Υ(10753)$ in the $4S$-$3D$ mixing scheme. Obviously, it is a good opportunity for the ongoing Belle II experiment if the predicted result in this work can be tested further.

hep-ph↗

arXiv2022

Spin and polarization analysis of $Z_{cs}$ state

A polarization analysis is performed for the recent observation of $Z_{cs}$ exotic state in the $e^+e^-$ annihilation experiment with motivation for measuring its spin quantum number in the future. Starting with the unpolarized electron and positron beam, the polarization transfer to the $Z_{cs}$ state and its decay angular distribution patterns are investigated. Some observables are suggested for determination of the spin parity quantum numbers. An ensemble of Monte-Carlo events are used to show some moment distributions special for manifestation of the different $Z_{cs}$ spin scenarios.

hep-ph↗

arXiv2021

Predicting another doubly charmed molecular resonance $T_{cc}^{\prime+}(3876)$

The isospin breaking effect plays an essential role in generating hadronic molecular states with a very tiny binding energy. Very recently, the LHCb Collaboration observed a very narrow doubly charmed tetraquark $T_{cc}^+$ in the $D^0D^0π$ mass spectrum, which lies just below the $D^0D^{*+}$ threshold around 273 keV. In this work, we study the $D^0D^{*+}/D^+D^{*0}$ interactions with the one-boson-exchange effective potentials and consider the isospin breaking effect carefully. We not only reproduce the mass of the newly observed $T_{cc}^+$ very well in the doubly charmed molecular tetraquark scenario, but also predict the other doubly charmed partner resonance $T_{cc}^{\prime+}$ with $m=3876~\text{MeV}$, and $Γ= 412~\text{keV}$. The prime decay modes of the $T_{cc}^{\prime+}$ are $D^0D^+γ$ and $D^+D^0π^0$. The peculiar characteristic mass spectrum of the $D^0D^{*+}/D^+D^{*0}$ molecular systems can be applied to identify the doubly charmed molecular states.

hep-ph↗

arXiv2021

Weakly-supervised Generative Adversarial Networks for medical image classification

Weakly-supervised learning has become a popular technology in recent years. In this paper, we propose a novel medical image classification algorithm, called Weakly-Supervised Generative Adversarial Networks (WSGAN), which only uses a small number of real images without labels to generate fake images or mask images to enlarge the sample size of the training set. First, we combine with MixMatch to generate pseudo labels for the fake images and unlabeled images to do the classification. Second, contrastive learning and self-attention mechanism are introduced into the proposed problem to enhance the classification accuracy. Third, the problem of mode collapse is well addressed by cyclic consistency loss. Finally, we design global and local classifiers to complement each other with the key information needed for classification. The experimental results on four medical image datasets show that WSGAN can obtain relatively high learning performance by using few labeled and unlabeled data. For example, the classification accuracy of WSGAN is 11% higher than that of the second-ranked MIXMATCH with 100 labeled images and 1000 unlabeled images on the OCT dataset. In addition, we also conduct ablation experiments to verify the effectiveness of our algorithm.

cs.CV↗

arXiv2021

On chip scalable highly pure and indistinguishable single photon sources in ordered arrays: Path to Quantum Optical Circuits

Realization of quantum optical circuits is at the heart of quantum photonic information processing. A long-standing obstacle however has been the absence of a platform of single photon sources (SPSs) that simultaneously satisfies the following required characteristics: spatially ordered SPS arrays that produce, on-demand, highly pure, and indistinguishable single photons with sufficiently uniform emission characteristics across the array, needed for controlled interference between photons from distinct sources to enable functional quantum optical networks. Here we report on such a platform of SPSs based upon a novel class of epitaxial quantum dots. Under resonant excitation, the SPSs (without Purcell enhancement) show single photon purity >99% (g(2)(0) ~ 0.015), high two-photon Hong-Ou-Mandel interference visibilities of 0.82 $\pm$ 0.03 (at 11.5K), and spectral nonuniformity <3nm - within established locally tunable technology. Our platform of SPSs paves the path to creating on-chip scalable quantum photonic systems.

quant-ph↗

arXiv2021

Observation of many-body quantum phase transitions beyond the Kibble-Zurek mechanism

Quantum critical behavior of many-body phase transitions is one of the most fascinating yet challenging questions in quantum physics. Here, we improved the band-mapping method to investigate the quantum phase transition from superfluid to Mott insulators, and we observed the critical behaviors of quantum phase transitions in both dynamical steady-state-relaxation region and phase-oscillation region. Based on various observables, two different values for the same quantum critical parameter are observed. This result is beyond a universal-scaling-law description of quantum phase transitions known as the Kibble-Zurek mechanism, and suggests that multiple quantum critical mechanisms are competing in many-body quantum phase transition experiments in inhomogeneous systems.

quant-ph↗

arXiv2021

KAISA: An Adaptive Second-Order Optimizer Framework for Deep Neural Networks

Kronecker-factored Approximate Curvature (K-FAC) has recently been shown to converge faster in deep neural network (DNN) training than stochastic gradient descent (SGD); however, K-FAC's larger memory footprint hinders its applicability to large models. We present KAISA, a K-FAC-enabled, Adaptable, Improved, and ScAlable second-order optimizer framework that adapts the memory footprint, communication, and computation given specific models and hardware to improve performance and increase scalability. We quantify the tradeoffs between memory and communication cost and evaluate KAISA on large models, including ResNet-50, Mask R-CNN, U-Net, and BERT, on up to 128 NVIDIA A100 GPUs. Compared to the original optimizers, KAISA converges 18.1-36.3% faster across applications with the same global batch size. Under a fixed memory budget, KAISA converges 32.5% and 41.6% faster in ResNet-50 and BERT-Large, respectively. KAISA can balance memory and communication to achieve scaling efficiency equal to or better than the baseline optimizers. KAISA is open source and available at https://github.com/gpauloski/kfac_pytorch.

cs.LG↗

arXiv2021

Proposal to detect a moving triangle singularity in $ψ(2S) \to π^+ π^- K^+ K^-$ process

In this work, we propose that there exists a moving triangle singularity in the $ψ(2S) \to π^+ π^- K^+ K^-$ process, whose position can vary from 1.158 to 1.181 GeV in the invariant mass spectrum of $K^+K^-$. After a precise analysis on this process, it turns out that after doing some cuts on $m_{π^+π^-}$, experiments do have the opportunity to observe this triangle singularity. In addition, when changing the cuts on $m_{π^+π^-}$, the movement of the predicted triangle singularity can also be observed. Thus, we suggest future experiments, especially Super Tau-Charm Facility (STCF), to do an anlysis on the $ψ(2S) \to π^+ π^- K^+ K^-$ process to verify our prediction.

hep-ph↗

arXiv2021

Hidden-bottom hadronic decays of $Υ(10753)$ with a $η^{(\prime)}$ or $ω$ emission

In this work, we propose the $4S$-$3D$ mixing scheme to assign the $Υ(10753)$ into the conventional bottomonium family. Under this interpretation, we further study its hidden-bottom hadronic decays with a $η^{(\prime)}$ or $ω$ emission, which include $Υ(10753)\toΥ(1S)η^{(\prime)}$, $Υ(10753)\to h_{b}(1P)η$ and $Υ(10753)\toχ_{bJ}ω$ ($J$=0,1,2) processes. Since the $Υ(10753)$ is above the $B\bar{B}$ threshold, the coupled-channel effect cannot be ignored, thus, when calculating partial decay widths of these $Υ(10753)$ hidden-bottom decays, we apply the hadronic loop mechanism. Our result shows that these discussed decay processes own considerable branching fractions with the order of magnitude of $10^{-4}\sim 10^{-3}$, which can be accessible at Belle II and other future experiments.

hep-ph↗

arXiv2021

Detecting the pure triangle sigularity effect through the $ψ(2S) \to p \bar{p} η/ p \bar{p} π^0$ process

In this work, the triangle singularity mechanism is investigated in the $ψ(2S) \to p \bar{p} η/ p \bar{p} π^0$ process. The triangle loop composed by $J/ψ$, $η$ and $p$ has a singularity in the physical kinematic range for the $ψ(2S) \to p \bar{p} η/ p \bar{p} π^0$ process, and it would generate a very narrow peak in the invariant mass spectrum of $pη(π)$ around $1.56387$ GeV, which is far away from both the threshold and relative resonances. In these processes, all the involved vertices are constrained by the experimental data. Thus, we can make a precise model independent prediction here. It turns out that the peak in the $pη$ invariant mass spectrum is visible, while it is very small in the $pπ^0$ invariant mass spectrum. We expect this effect shown in $p \bar{p} η$ final state can be observed by the Beijing Spectrometer (BESIII) and Super Tau-Charm Facility (STCF) in the future.

hep-ph↗

arXiv2021

Detecting the polarization in $χ_{cJ} \to ϕϕ$ decays to probe hadronic loop effect

In this work, we propose that detecting the polarization information of $χ_{cJ}\to ϕϕ~(J=0,1,2)$ can be as good test of the role of hadronic loop effect on these decays. Our results shows that the obtained ratios of helicity amplitudes are quite stable, which are $|F_{1,1}^{(0)}/F_{0,0}^{(0)}| \approx 0.359$, $|F_{1,0}^{(1)}/F_{0,1}^{(1)}| =1$, $|F_{1,1}^{(1)}/F_{0,1}^{(1)}| =0$, $|F^{(2)}_{1,0}|/|F^{(2)}_{0,0}|=|F^{(2)}_{0,1}|/|F^{(2)}_{0,0}| \approx 1.285,~|F^{(2)}_{1,-1}|/|F^{(2)}_{0,0}|=|F^{(2)}_{-1,1}|/|F^{(2)}_{0,0}| \approx 5.110$ and $|F^{(2)}_{-1,-1}|/|F^{(2)}_{0,0}|=|F^{(2)}_{1,1}|/|F^{(2)}_{0,0}| \approx 0.465$. By adopting these predicted ratios, we further generate Monte-Carlo events of moments $\langle t_{ij} \rangle$, which are directly related to the determination of helicity amplitudes. We suggest further experiments like BESIII and Belle II to perform an analysis on the polarizations of the $χ_{cJ}\to ϕϕ$ process in the future, which is important to understand the underlying decay mechanism existing in $χ_{cJ}$ decays.

hep-ph↗