papers

Publications (28)

cs.AR2021

HyCA: A Hybrid Computing Architecture for Fault Tolerant Deep Learning

Cheng Liu, Cheng Chu, Dawen Xu +5

Hardware faults on the regular 2-D computing array of a typical deep learning accelerator (DLA) can lead to dramatic prediction accuracy loss. Prior redundancy design approaches ty…

quant-ph2025

BVQC: A Backdoor-style Watermarking Scheme for Variational Quantum Circuits

Cheng Chu, Lei Jiang, Fan Chen

Variational Quantum Circuits (VQCs) have emerged as a powerful quantum computing paradigm, demonstrating a scaling advantage for problems intractable for classical computation. As…

cs.AR2021

Energy-Efficient Accelerator Design for Deformable Convolution Networks

Dawen Xu, Cheng Chu, Cheng Liu +4

Deformable convolution networks (DCNs) proposed to address the image recognition with geometric or photometric variations typically involve deformable convolution that convolves on…

math.CA2013

A Characterization of

Cheng Chu

We characterize the set of all measurable functions on $\RR^n$ possessing an majorant, denoted as $\cM_{A_1}(\RR^n)$, by certain Banach function spaces. We prove that a funct…

quant-ph2024

QuantumLeak: Stealing Quantum Neural Networks from Cloud-based NISQ Machines

Zhenxiao Fu, Min Yang, Cheng Chu +3

Variational quantum circuits (VQCs) have become a powerful tool for implementing Quantum Neural Networks (QNNs), addressing a wide range of complex problems. Well-trained VQCs serv…

cs.CR2026

Selective KV-Cache Sharing to Mitigate Timing Side-Channels in LLM Inference

Kexin Chu, Zecheng Lin, Dawei Xiang +7

Global KV-cache sharing is an effective optimization for accelerating large language model (LLM) inference, yet it introduces an API-visible timing side channel that lets adversari…

quant-ph2023

CryptoQFL: Quantum Federated Learning on Encrypted Data

Cheng Chu, Lei Jiang, Fan Chen

Recent advancements in Quantum Neural Networks (QNNs) have demonstrated theoretical and experimental performance superior to their classical counterparts in a wide range of applica…

quant-ph2023

IQGAN: Robust Quantum Generative Adversarial Network for Image Synthesis On NISQ Devices

Cheng Chu, Grant Skipper, Martin Swany +1

In this work, we propose IQGAN, a quantum Generative Adversarial Network (GAN) framework for multiqubit image synthesis that can be efficiently implemented on Noisy Intermediate Sc…

cs.ET2022

QMLP: An Error-Tolerant Nonlinear Quantum MLP Architecture using Parameterized Two-Qubit Gates

Cheng Chu, Nai-Hui Chia, Lei Jiang +1

Despite potential quantum supremacy, state-of-the-art quantum neural networks (QNNs) suffer from low inference accuracy. First, the current Noisy Intermediate-Scale Quantum (NISQ)…

math.CV2014

Asymptotic Bohr Radius for the Polynomials in One Complex Variable

Cheng Chu

We consider the Bohr radius for the class of complex polynomials in one variable of degree at most . It was conjectured by R. Fournier in 2008 that $R_n={1\over 3}+{π^2\o…

math.FA2020

Product of truncated Hankel and truncated Toeplitz operators

Cheng Chu

A truncated Toeplitz operator is the compression of a classical Toeplitz operator on the Hardy space to a model space. A truncated Hankel operator is the compression of a Hankel op…

math.FA2017

Normal Truncated Toeplitz Operators

Cheng Chu

The characterization of normal truncated Toepltiz operators is first given by Chalendar and Timotin. We give an elementary proof of their result without using the algebraic propert…

math.FA2018

Reducing Subspaces of de Branges-Rovnyak Spaces

Cheng Chu

For , the closed unit ball of , the de Branges-Rovnyak spaces is a Hilbert space contractively contained in the Hardy space that i…

math.FA2018

Hilbert Spaces Contractively Contained in Weighted Bergman Spaces on the Unit Disk

Cheng Chu

Sub-Bergman Hilbert spaces are analogues of de Branges-Rovnyak spaces in the Bergman space setting. They are reproducing kernel Hilbert spaces contractively contained in the Bergma…

quant-ph2024

QDoor: Exploiting Approximate Synthesis for Backdoor Attacks in Quantum Neural Networks

Cheng Chu, Fan Chen, Philip Richerme +1

Quantum neural networks (QNNs) succeed in object recognition, natural language processing, and financial analysis. To maximize the accuracy of a QNN on a Noisy Intermediate Scale Q…

math.FA2020

Which de Branges-Rovnyak spaces have complete Nevanlinna-Pick property?

Cheng Chu

We characterize the de Branges-Rovnyak spaces with complete Nevanlinna-Pick property. Our method relies on the general theory of reproducing kernel Hilbert spaces.

math.CV2018

Density of Polynomials in Sub-Bergman Hilbert Spaces

Cheng Chu

The sub-Bergman Hilbert spaces are analogues of de BrangesRovnyak spaces in the Bergman space setting. We prove that the polynomials are dense in sub-Bergman Hilbert spaces. This a…

math.CV2018

Bounded Composition Operators and Multipliers of Some Reproducing Kernel Hilbert Spaces on the Bidisk

Cheng Chu

We study the boundedness of composition operators on the bidisk using reproducing kernels. We show that a composition operator is bounded on the Hardy space of the bidisk if some a…

quant-ph2026

SoK: Adversarial Robustness of the Variational Quantum Eigensolver via Red-Teaming

Ahmed Azaz Humdoon, Cheng Chu, Lei Jiang +2

The Variational Quantum Eigensolver (VQE) is a leading algorithm for estimating molecular ground-state energies on near-term quantum hardware, with applications spanning quantum ch…

quant-ph2025

LSTM-QGAN: Scalable NISQ Generative Adversarial Network

Cheng Chu, Aishwarya Hastak, Fan Chen

Current quantum generative adversarial networks (QGANs) still struggle with practical-sized data. First, many QGANs use principal component analysis (PCA) for dimension reduction,…

math.FA2021

A Gleason-Kahane-Żelazko theorem for reproducing kernel Hilbert spaces

Cheng Chu, Michael Hartz, Javad Mashreghi +1

We establish the following Hilbert-space analogue of the Gleason-Kahane-Å»elazko theorem. If is a reproducing kernel Hilbert space with a normalized complete Pick ker…

math.FA2014

Compact Product of Hankel and Toeplitz Operators

Cheng Chu

In this paper, we study the product of a Hankel operator and a Toeplitz operator on the Hardy space. We give necessary and sufficient conditions of when such a product is…

quant-ph2026

Hardware Robustness of Sample-Based Quantum Diagonalization

Ahatesham Bhuiyan, Cheng Chu, Qian Lou +1

Sample-based Quantum Diagonalization (SQD) is a hybrid quantum-classical method that replaces variational optimization with a self-consistent recovery loop over QPU samples. Althou…

quant-ph2023

QTrojan: A Circuit Backdoor Against Quantum Neural Networks

Cheng Chu, Lei Jiang, Martin Swany +1

We propose a circuit-level backdoor attack, \textit{QTrojan}, against Quantum Neural Networks (QNNs) in this paper. QTrojan is implemented by few quantum gates inserted into the va…

quant-ph2026

CutBackdoor: A Circuit Cut Triggered Backdoor Attack on Variational Quantum Algorithms

Ahatesham Bhuiyan, Hoang Ngo, Cheng Chu +4

Variational Quantum Algorithms (VQAs) are a leading paradigm for near-term quantum computing, combining parameterized quantum circuits with classical optimization across quantum ch…

quant-ph2024

TITAN: A Distributed Large-Scale Trapped-Ion NISQ Computer

Cheng Chu, Zhenxiao Fu, Yilun Xu +4

Trapped-Ion (TI) technology offers potential breakthroughs for Noisy Intermediate Scale Quantum (NISQ) computing. TI qubits offer extended coherence times and high gate fidelity, m…

cs.CR2024

OFHE: An Electro-Optical Accelerator for Discretized TFHE

Mengxin Zheng, Cheng Chu, Qian Lou +4

This paper presents \textit{OFHE}, an electro-optical accelerator designed to process Discretized TFHE (DTFHE) operations, which encrypt multi-bit messages and support homomorphic…

math.CV2015

A Note on the Spectral Area of Toeplitz Operators

Cheng Chu, Dmitry Khavinson

In this note, we show that for hyponormal Toeplitz operators, there exists a lower bound for the area of the spectrum. This extends the known estimate for the spectral area of Toep…