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PRX Quantum
Scopus
ISSN 2691-3399 · American Physical Society · 1,354 articles in the index
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Journal Article
Classical Algorithms for Measurement-Adaptive Gaussian Circuits
Gaussian building blocks are essential for photonic quantum information processing, and universality can be practically achieved by equipping Gaussian circuits with adaptive measurement and feedforward. The number of adaptive steps then provides a natural parameter for computational power. Rather…
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Journal Article
Quantum Simulation with Rydberg Ions in a Penning Trap
Quantum simulation of interacting many-body spin systems is routinely performed with cold trapped ions, and systems with hundreds of spins have been studied in one and two dimensions. In the most common realizations of these platforms, spin degrees of freedom are encoded in low-lying electronic…
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Journal Article
Electrically Tunable Orbital Coupling and Quantum Light Emission from O-Band Quantum Dot Molecules
We present the observation of electrically tunable quantum coupling of orbital states in individual InAs/InGaAs quantum dot molecules emitting in the telecom O-band (∼1.3 μm). By tuning the static electric field along the growth axis of the quantum dot (QD)-molecule, we observe pronounced…
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Journal Article
Frequency- and Amplitude-Modulated Gates for Universal Quantum Control
Achieving high-fidelity single- and two-qubit gates is essential for executing arbitrary digital quantum algorithms and for building error-corrected quantum computers. We propose a theoretical framework for implementing quantum gates using frequency- and amplitude-modulated microwave control…
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Journal Article
Universal Sample Complexity Bounds in Quantum Learning Theory via Fisher Information Matrix
In this work, we show that the sample complexity required in quantum learning theory within a general parametric framework is fundamentally governed by the inverse Fisher information matrix. More specifically, we derive upper and lower bounds on the number of samples required to estimate the…
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Journal Article
Improving Variational Counterdiabatic Driving with Weighted Actions and Computer Algebra
Variational counterdiabatic (CD) driving is a disciplined and widely used method to robustly control quantum many-body systems by mimicking adiabatic processes with high fidelity and reduced duration. Central to this technique is a universal structure of the adiabatic gauge potential (AGP) over a…
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Journal Article
Incorporating Device Characterization into Security Proofs
Typical security proofs for quantum key distribution (QKD) rely on having some model for the devices, with the security guarantees implicitly relying on the values of various parameters of the model, such as dark count rates or detector efficiencies. Hence to deploy QKD in practice, we must…
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Journal Article
Nondegenerate Josephson Mixers with Enhanced Bandwidth and Saturation Power for Quantum Signal Amplification and Transduction
Nondegenerate Josephson mixers (JMs), formed by coupling two different transmission-line resonators to Josephson ring modulators (JRMs), are vital and versatile devices capable of processing microwave signals at the quantum limit. Owing to the lossless nondegenerate three-wave mixing process…
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Journal Article
Nontrivial Multiproduct Commutation Relation Toward Reducing T-Count in Sequential Pauli-Based Computation
Quantum compilers that reduce the number of T gates are essential for minimizing the overhead of fault-tolerant quantum computation. Achieving further T-count reduction calls for identifying equivalent circuit transformation rules beyond those utilized in existing tools. In this paper, we rewrite…
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Journal Article
Color It, Code It, Cancel It: k-Local Dynamical Decoupling from Classical Additive Codes
Dynamical decoupling is a central technique in quantum computing for actively suppressing decoherence and systematic imperfections through sequences of single-qubit operations. Conventional sequences typically aim to completely freeze system dynamics, often resulting in long protocols whose length…
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Journal Article
Realization of an All-Optical Effective Negative-Mass Oscillator for Coherent Quantum Noise Cancellation
We report the realization of an all-optical, tabletop effective negative-mass oscillator (ENMO) scheme capable of canceling quantum noise when cascaded with an optomechanical sensor susceptible to (quantum) radiation pressure noise. Our coherent quantum noise cancellation (CQNC) scheme offers a…
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Journal Article
Estimates of Loss Function Concentration in Noisy Parametrized Quantum Circuits
Variational quantum computing offers a powerful framework with applications across diverse fields such as quantum chemistry, machine learning, and optimization. However, its scalability is hindered by the exponential concentration of the loss function, known as the barren plateau problem. While…
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Journal Article
Transversal Architecture for Megaquop-Scale Quantum Simulation with Neutral Atoms
Quantum computing experiments have made remarkable progress in demonstrating key components of error-corrected quantum computing, a prerequisite for scalable quantum computation. While we anticipate the near-term arrival of early fault-tolerant quantum hardware capable of a million reliable quantum…
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Journal Article
Abelian State Hidden Subgroup Problem: Learning Stabilizer Groups and Beyond
Identifying the symmetry properties of quantum states is a central theme in quantum information theory and quantum many-body physics. In this work, we investigate quantum learning problems in which the goal is to identify a hidden symmetry of an unknown quantum state. Building on the recent…
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Journal Article
Fourier Neural Operators for Time-Periodic Quantum Systems: Learning Floquet Hamiltonians, Observable Dynamics, and Operator Growth
Time-periodic quantum systems exhibit a rich variety of far-from-equilibrium phenomena and serve as ideal platforms for quantum engineering and control. However, simulating their dynamics with conventional numerical methods remains challenging due to the exponential growth of Hilbert space…
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Journal Article
Quantifying Robustness and Locality of Majorana Bound States in Interacting Systems
Protecting qubits from perturbations is a central challenge in quantum computing. Topological superconductors with separated Majorana bound states (MBSs) provide a strong form of protection that only depends on the locality of perturbations. While the link between MBS separation, robust degeneracy…
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Journal Article
Erasure Conversion in Integer Fluxonium Qubits
We propose an erasure conversion scheme on the |e⟩−|f⟩ and |g⟩−|f⟩ qubits in integer fluxonium qubits (IFQs), which are both first-order insensitive to 1/f flux noise. The |e⟩−|f⟩ transition is identical to that of a usual fluxonium qubit and hence is expected to have excellent coherence time…
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Journal Article
Exploring the Riemann-Surface Topology of a Non-Hermitian Superconducting Qubit Using Shortcuts to Adiabaticity
Open quantum systems described by a non-Hermitian Hamiltonian exhibit rich dynamics due to the topology of their complex energy spectrum. By encircling an exceptional point degeneracy, this topology allows for topological state transport, chiral geometric phases, and eigenvalue braiding. To access…
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Journal Article
Omnidirectional Shuttling to Avoid Valley Excitations in Si/SiGe Quantum Wells
Conveyor-mode shuttling is a key approach for implementing intermediate-range coupling between electron-spin qubits in quantum dots. Initial implementations are encouraging; however, long shuttling trajectories are guaranteed to encounter regions of low conduction-band valley-energy splittings, due…
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Journal Article
Decoding across Transversal Clifford Gates in the Surface Code
Transversal logical gates offer the opportunity for fast and low-noise logic, particularly when interspersed by a single round of parity check measurements of the underlying code. Using such circuits for the surface code requires decoding across logical gates, complicating the decoding task. We…
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