Papers
Critical Unstable Qubits in Particle Physics
Dimitrios Karamitros, Thomas McKelvey, Snehit Panghal +1 more·Mar 12, 2026
We study in detail the dynamics of unstable two-level quantum systems by adopting the Bloch-vector representation. We identify a novel class of critical scenarios in which the so-called energy-level and decay-width vectors, ${\bf E}$ and ${\bfΓ}$, ar...
Compactifying the Electronic Wavefunction II: Quantum Estimators for Spin-Coupled Generalized Valence Bond Wavefunctions
Bruna Gabrielly·Mar 12, 2026
We present a measurement-driven quantum framework for evaluating overlap and Hamiltonian matrix elements in spin-coupled generalized valence bond (SCGVB) wavefunctions. The approach targets a central difficulty of nonorthogonal valence-bond methods: ...
From vacuum amplitudes to qubits
Germán Rodrigo·Mar 12, 2026
High-energy colliders, exemplified by the CERN's Large Hadron Collider (LHC), constitute genuine quantum machines. In alignment with Richard Feynman's foundational vision for quantum computing, collider physics emerge therefore as a prime candidate f...
Quantum synchronization and chimera states in a programmable quantum many-body system
Kazuya Shinjo, Kazuhiro Seki, Seiji Yunoki·Mar 12, 2026
Synchronization is a hallmark of collective behavior in classical nonlinear systems, yet its realization as a robust many-body phenomenon in coherent quantum systems remains largely unexplored. Here we demonstrate symmetry-protected quantum synchroni...
Probing the memory of a superconducting qubit environment
Nicolas Gosling, Denis Bénâtre, Nicolas Zapata +8 more·Mar 12, 2026
Achieving fault tolerance with superconducting quantum processors requires qubits to operate within the regime of threshold theorems based on the Born-Markov approximation. This approximation, which models dissipation as constant energy decay into a ...
Uniqueness of imaginarity-assisted transformation from computationally universal to strictly universal quantum computation
Yasuaki Nakayama, Yuki Takeuchi, Seiseki Akibue·Mar 12, 2026
The computational universality with an elementary gate set $\{H,CCZ\}$ can be transformed to the strict universality by using a maximally imaginary state $|+i\rangle$ and some non-imaginary ancillary qubits. From the viewpoint of operational resource...
Optimal quantum metrology protocols with erasure qubits
Michal Arieli, Alex Retzker, Tuvia Gefen·Mar 12, 2026
We investigate the precision limits and optimal protocols for sensing single qubit signals in the presence of erasure noise. We study a hierarchy of precision limits achievable with metrological strategies of differing complexity, and identify the op...
Demonstration of High-Fidelity Gates in a Strongly Anharmonic with Long-Coherence C-Shunt Flux Qubit
Silu Zhao, Li Li, Weiping Yuan +13 more·Mar 12, 2026
We demonstrate high-fidelity single-qubit gates on a C-shunt flux qubit that simultaneously combines a large anharmonicity ($\mathcal{A}/2π=848~\mathrm{MHz}$) with long relaxation time ($T_1 = 23~μ\text{s}$). The large anharmonicity significantly sup...
Quantum Reservoir Autoencoder for Blind Decryption: Two-Phase Protocol and Noise Resilience
Hikaru Wakaura, Taiki Tanimae·Mar 12, 2026
We instantiate the quantum reservoir autoencoder (QRA) with a noise-induced reservoir employing reset noise channels and address two open problems: noise-resilient reversibility and blind decryption. For a single-ciphertext protocol with 10 data qubi...
Quantum Error Correction by Purification
Jonathan Raghoonanan, Tim Byrnes·Mar 12, 2026
We present a general-purpose quantum error correction primitive based on state purification via the SWAP test, which we refer to as purification quantum error correction (PQEC). This method operates on $N$ noisy copies, requires minimally $O(M\log_2 ...
Impact of Oxygen Vacancies in Josephson Junction on Decoherence of Superconducting Qubits
Hanqin Bai, Shi-Yao Hou, Mu Lan·Mar 12, 2026
Superconducting quantum circuits are promising platforms for scalable quantum computing, where qubit coherence is critically determined by microscopic defects in the oxide tunneling barrier of Josephson junctions. Amorphous Al$_2$O$_3$ is widely used...
Saturable absorption in diamond nanophotonics
Christopher Coutts, Nicholas J. Sorensen, Elham Zohari +3 more·Mar 11, 2026
Diamond is a leading quantum photonics platform due to its ability to host qubits based on crystal defects such as nitrogen vacancy centres. Fabricating nanophotonic devices from defect-rich diamond, which is central to many quantum sensing technolog...
Rhenium as a material platform for long-lived transmon qubits
Yanhao Wang, Suhas Ganjam, Ishan Narra +2 more·Mar 11, 2026
Dielectric loss at the interfaces of superconducting films has long been recognized as limiting the performance of state-of-the-art superconducting circuits. Notably, the presence of a native oxide layer on the film is hypothesized to contribute to d...
Mitigating crosstalk errors for simultaneous single-qubit gates on a superconducting quantum processor
Jaap J. Wesdorp, Eric Hyyppä, Joona Andersson +61 more·Mar 11, 2026
Single-qubit gates on superconducting quantum processors are typically implemented using microwave pulses applied through dedicated control lines. However, these microwave pulses may also drive other qubits due to crosstalk arising from capacitive co...
Universality of Classically Trainable, Quantum-Deployed Boson-Sampling Generative Models
Andrii Kurkin, Ulysse Chabaud, Zoltán Kolarovszki +3 more·Mar 11, 2026
Recent work on the instantaneous quantum polynomial-time (IQP) quantum-circuit Born machine (QCBM) highlights a promising paradigm for generative modeling: train classically, deploy quantumly. In this setting, the training objective can be evaluated ...
Permutation-invariant codes: a numerical study and qudit constructions
Liam J. Bond, Jiří Minář, Māris Ozols +2 more·Mar 11, 2026
We investigate Permutation-Invariant (PI) quantum error-correcting codes encoding a logical qudit of dimension $\mathrm{d}_\mathrm{L}$ in PI states using physical qudits of dimension $\mathrm{d}_\mathrm{P}$. We extend the Knill--Laflamme (KL) conditi...
Hybridlane: A Software Development Kit for Hybrid Continuous-Discrete Variable Quantum Computing
Jim Furches, Timothy J. Stavenger, Carlos Ortiz Marrero·Mar 11, 2026
Hybrid quantum computing systems that combine discrete-variable qubits with continuous-variable qumodes offer promising advantages for quantum simulation, error correction, and sensing applications. However, existing quantum software frameworks lack ...
Feasibility of satellite-augmented global quantum repeater networks
Manik Dawar, Clement Paillet, Nilesh Vyas +3 more·Mar 11, 2026
A large scale quantum network requires the distribution of high-fidelity end-to-end entanglement. To overcome the range limitations inherent to terrestrial fiber, a leading architecture has emerged: satellite-based sources transmitting entanglement t...
High fidelity photon-photon gates by scattering off a two-level quantum emitter
Love A. Pettersson, Victor R. Christiansen, Klaus Mølmer +1 more·Mar 11, 2026
We present a scheme for implementing a high-fidelity non-linear phase shift on a photonic state. The scheme is based on repeated scattering off a two-level quantum emitter embedded in a chiral or one-sided waveguide. The waveguide is equipped with el...
Efficient and accurate two-qubit-gate operation in a high-connectivity transmon lattice utilizing a tunable coupling to a shared mode
Tuure Orell, Hao Hsu, Joona Andersson +3 more·Mar 11, 2026
Increasing connectivity and decreasing qubit-state delocalization without compromising the speed and accuracy of elementary gate operations are topical challenges in the development of large-scale superconducting quantum computers. In this theoretica...