Papers
Operational bounds and diagnostics for coherence in energy transfer
Julia Liebert, Gregory D. Scholes·Mar 10, 2026
Excitation energy transfer in light-harvesting aggregates is highly efficient, yet whether quantum coherence plays an operational role in transport remains debated. A central challenge is that coherence is usually inferred from spectroscopic signatur...
Efficient Qubit Simulation of Hybrid Oscillator-Qubit Quantum Computation
Xi Lu, Bojko N. Bakalov, Yuan Liu·Mar 10, 2026
We introduce a framework for simulating hybrid oscillator-qubit quantum processors on qubit-only systems through position encoding. By encoding continuous-variable position and momentum wave functions into qubit amplitudes, our method efficiently sim...
High-optical-depth, sub-Doppler-width absorption lines at telecom wavelengths in hot, optically driven rubidium vapor
Inna Kviatkovsky, Lucas Pache, Viola-Antonella Zeilberger +4 more·Mar 9, 2026
Doppler broadening presents a major limitation for high-resolution spectroscopy and nonlinear optics in room-temperature atomic vapors. Here, we demonstrate the suppression of Doppler broadening accompanied by pronounced absorption on the upper trans...
Scalable Postselection of Quantum Resources
J. Wilson Staples, Winston Fu, Jeff D. Thompson·Mar 9, 2026
The large overhead imposed by quantum error correction is a critical challenge to the realization of quantum computers, and motivates searching for alternative error correcting codes and fault-tolerant circuit constructions. Postselection is a powerf...
Practical implementation of arbitrary nonlocal controlled-unitary gate via indefinite causal order
Wen-Qiang Liu, Zi-Han Zheng, Zhang-Qi Yin +1 more·Mar 9, 2026
Quantum gate teleportation enables the implementation of nonlocal quantum operations without direct interactions between distant nodes. We propose an efficient protocol for implementing arbitrary controlled-unitary (CU) gates acting on two spatially ...
Deterministic Discrimination of Phase-Modified Permutation Oracles via Single Qubit Measurement
Owen Root·Mar 8, 2026
I study a promise problem for an unknown unitary operator acting on an $n$-qubit system. The operator is promised to take one of two forms: either it implements a fixed permutation of computational basis states, or it implements the same permutation ...
Entangling ions with engineered light gradients
Tommaso Faorlin, Lorenz Panzl, Phoebe Grosser +12 more·Mar 8, 2026
Spectral crowding of collective motional modes limits the fidelity of entangling interactions in trapped-ion quantum processors by inducing off-resonant coupling to spectator modes. We introduce a geometric-phase entangling interaction driven by a tr...
Sharpening Worst-Case Error Assessment for Fault-Tolerant Quantum Computing: Fidelity and Its Deviation
Kyoungho Cho, Ilkwon Sohn, Yongsoo Hwang +1 more·Mar 8, 2026
Gate fidelity -- an average fidelity over all possible input states -- is the workhorse metric for benchmarking quantum gates or circuits, yet fault-tolerant quantum computing ultimately depends on the worst-case behavior, typically quantifiable by s...
Long-time storage of entangled logical states in decoherence-free subspaces
L. Zhang, Y. -L. Xu, Y. -K. Wu +11 more·Mar 7, 2026
The maintenance of quantum entanglement lays the elementary building block of quantum information processing, requiring an integration of long coherence time, sufficient storage capacity, and high-fidelity entangling gates. Here we encode two-qubit e...
Radio-Frequency Side-Channel Analysis of a Trapped-Ion Quantum Computer
Giorgio Grigolo, Dorian Schiffer, Lukas Gerster +2 more·Mar 6, 2026
Analogously to classical computers, quantum processors exhibit side channels that may give attackers access to potentially proprietary algorithms. We identify and exploit a previously unexplored side channel in trapped-ion quantum processors that ari...
A Mixture-of-Experts Framework for Practical Hybrid-Quantum Models in Credit Card Fraud Detection
Rodrigo Chaves, Kunal Kumar, Bruno Chagas +4 more·Mar 6, 2026
This paper investigates whether hybrid quantum-classical machine learning can deliver practical improvements in financial fraud detection performance for card-based and other payment transactions. Building on a Guided Quantum Compressor architecture,...
Unifying Graph Measures and Stabilizer Decompositions for the Classical Simulation of Quantum Circuits
Julien Codsi, Tuomas Laakkonen·Mar 6, 2026
Various algorithms have been developed to simulate quantum circuits on classical hardware. Among the most prominent are approaches based on \emph{stabilizer decompositions} and \emph{tensor network contraction}. In this work, we present a unified fra...
Quantum algorithm for the collision-coalescence of cloud droplets
Kazumasa Ueno, Hiroaki Miura·Mar 6, 2026
Quantum computing is gaining attention as a new approach for solving complex problems in many scientific fields. In atmospheric and oceanic sciences, it may help reduce computational costs of simulating large and nonlinear systems. However, research ...
Variational Quantum Operator Simulation
Satoru Shoji, Kosuke Ito, Yukihiro Shimizu +1 more·Mar 6, 2026
Implementing time-evolution operators in shallow quantum circuits is important for quantum simulations. The standard method of Trotterization requires a large number of gates to achieve practical accuracy. Variational Quantum Simulation (VQS) is an a...
Characterizing Noise Effects on Multipartite Entanglement via Phase-Space Visualization
B Nithya Priya, S. Saravana Veni, Araceli Venegas-Gomez +1 more·Mar 6, 2026
This paper investigates the behavior of two fundamental types of multipartite entangled states, namely GHZ(3) and W(3) states under Gaussian-distributed amplitude perturbations and White noise model. The Uhlmann-Jozsa fidelity is taken to be the quan...
Classical simulability of quantum circuits followed by sparse classical post-processing
Yasuhiro Takahashi, Masayuki Miyamoto, Noboru Kunihiro·Mar 6, 2026
We study the classical simulability of a polynomial-size quantum circuit $C_n$ on $n$ qubits followed by sparse classical post-processing (SCP) on $m$ bits, where $m \leq n \leq {\rm poly}(m)$. The SCP is described by a non-zero Boolean function $f_m...
Heterogeneous entanglement between a trapped ion and a solid-state quantum memory
Chen-Xu Wang, Yi-Yang Wang, Tian-Xiang Zhu +11 more·Mar 6, 2026
Hybrid quantum networks offer a promising architecture for scalable quantum information processing and a future quantum internet, as they can combine the complementary strengths of disparate physical platforms. While single-atom systems provide deter...
Matchgate circuit representation of fermionic Gaussian states: optimal preparation, approximation, and classical simulation
Marc Langer, Raúl Morral-Yepes, Adam Gammon-Smith +2 more·Mar 5, 2026
Fermionic Gaussian states (FGSs) and the associated matchgate circuits play a central role in quantum information theory and condensed matter physics. Despite being possibly highly entangled, they can still be efficiently simulated on classical compu...
Universal quantum computation with group surface codes
Naren Manjunath, Vieri Mattei, Apoorv Tiwari +1 more·Mar 5, 2026
We introduce group surface codes, which are a natural generalization of the $\mathbb{Z}_2$ surface code, and equivalent to quantum double models of finite groups with specific boundary conditions. We show that group surface codes can be leveraged to ...
High-performance syndrome extraction circuits for quantum codes
Armands Strikis, Dan E. Browne, Michael E. Beverland·Mar 5, 2026
We present a fast and effective framework for analysing and designing syndrome-extraction circuits (SECs). Our approach is based on left-right circuits, a general design for SECs which maintain low depth by staggering $X$ and $Z$ checks without inter...