Papers
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...
Efficiently Learning Global Quantum Channels with Local Tomography
Zidu Liu, Dominik S. Wild·Mar 7, 2026
Scalable characterization of quantum processors is crucial for mitigating noise and imperfections. While randomized measurement protocols enable efficient access to local observables, inferring a globally consistent description of multi-qubit process...
Qubit Noise Sensing via Induced Photon Loss in a Superconducting Cavity
Nitzan Kahn, Dror Garti, Uri Goldblatt +3 more·Mar 6, 2026
Characterizing noise in superconducting qubits is essential for improving coherence and gate performance. Conventional noise-sensing methods typically use the qubit itself as the sensor, which limits both accessible bandwidth and applicability during...
Heterogeneous quantum error-correcting codes
Omid Khosravani, Guillermo Escobar-Arrieta, Kenneth R. Brown +1 more·Mar 6, 2026
We introduce heterogeneous quantum error-correcting codes composed of qubit types with distinct error channels and study their performance in the code-capacity regime using maximum-likelihood tensor network decoding. In the regime where both qubit ty...
Quantum Technologies and Edge Devices in Electrical Grids: Opportunities, Challenges, and Future Directions
Marjorie Hoegen, René Glebke, M. Sahnawaz Alam +11 more·Mar 6, 2026
In modern power systems, edge devices serve as local hubs that collect data, perform on-site computing, sense electrical parameters, execute control actions, and communicate with neighboring edge devices as part of the larger grid. However, as the nu...
Hybrid quantum-classical simulations of semiclassical gravity
Carlos Fulgado-Claudio, Daniel González-Cuadra, Jose Beltrán Jiménez +1 more·Mar 6, 2026
We propose a hybrid quantum-classical algorithm for the simulation of real-time dynamics in interacting quantum field theories coupled to classical fields, focusing on the self-consistent estimation of semiclassical backreaction. By discretizing spac...
Score Reversal Is Not Free for Quantum Diffusion Models
Ammar Fayad·Mar 6, 2026
Classical reverse diffusion is generated by changing the drift at fixed noise. We show that the quantum version of this principle obeys an exact law with a sharp phase boundary. For Gaussian pure-loss dynamics, the canonical model of continuous-varia...
Entanglement is not sufficient for most practical entanglement-based QKD protocols
Shubhayan Sarkar, Tushita Prasad, Karol Horodecki·Mar 6, 2026
Quantum key distribution (QKD) is the most explored application of quantum information theory. A central problem in entanglement-based QKD (EB-QKD), is whether every entangled state can be used to extract a key. We observe that entanglement is not su...
Leakage-protected idle operation of a triangular exchange-only spin qubit
Joseph D. Broz, Jesse C. Hoke, Edwin Acuna +1 more·Mar 6, 2026
We characterize the coherence of a triangular exchange-only (EO) spin qubit operated at a leakage-protected idle (LPI) point. The triangular geometry enables independent control of all three pairwise exchange interactions, and the LPI condition occur...
Belief-Adaptive MAP Detection for Molecular ISI Channels with Heteroscedastic Noise
Erencem Ozbey, H. Birkan Yilmaz, Chan-Byoung Chae·Mar 6, 2026
Inter-symbol interference (ISI) with heteroscedastic, or state-dependent, noise is a defining feature of molecular communication via diffusion (MCvD). However, such noise variance dependency across ISI states has not been systematically considered in...
Unified and computable approach to optimal strategies for multiparameter estimation
Zhao-Yi Zhou, Da-Jian Zhang·Mar 6, 2026
Precise estimation of physical parameters underpins both scientific discovery and technological development. A central goal of quantum metrology and sensing is to exploit quantum resources like entanglement to devise optimal strategies for estimating...
Macroscopic entanglement distribution with atomic ensembles
Shuang Li, Jin Hu, Ilia D. Lazarev +4 more·Mar 6, 2026
The distribution of entanglement is a crucial task for quantum communication towards realizing a globe-spanning quantum internet. Recently a protocol for deterministic long-distance distribution of macroscopic entanglement over a network of ensembles...
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...
Multi-Shot Quantum Sensing for RF Signal Detection with MIMO Rydberg-Atom Receivers
Saman Atapattu, Harini Hapuarachchi, Nathan Ross·Mar 6, 2026
Rydberg-atom quantum receivers (RAQRs) enable electric-field sensing with quantum-noise-limited performance, yet their optical readout provides only magnitude measurements whose fluctuations follow Rician statistics governed by atomic projection nois...
Decoder Performance in Hybrid CV-Discrete Surface-Code Threshold Estimation Using LiDMaS+
Dennis Delali Kwesi Wayo, Chinonso Onah, Leonardo Goliatt +1 more·Mar 6, 2026
Threshold estimation is central to fault-tolerant quantum computing, but the reported threshold depends not only on the code and noise model, but also on the decoder used to interpret syndrome data. We study this dependence for surface-code threshold...
Mirror codes: High-threshold quantum LDPC codes beyond the CSS regime
Andrey Boris Khesin, Jonathan Z. Lu·Mar 5, 2026
The realization of quantum error correction protocols whose logical error rates are suppressed far below physical error rates relies on an intricate combination: the error-correcting code's efficiency, the syndrome extraction circuit's fault toleranc...
Ansatz-Free Learning of Lindbladian Dynamics In Situ
Petr Ivashkov, Nikita Romanov, Weiyuan Gong +3 more·Mar 5, 2026
Characterizing the dynamics of open quantum systems at the level of microscopic interactions and error mechanisms is essential for calibrating quantum hardware, designing robust simulation protocols, and developing tailored error-correction methods. ...
Spatiotemporal Pauli processes: Quantum combs for modelling correlated noise in quantum error correction
John F Kam, Angus Southwell, Spiro Gicev +2 more·Mar 5, 2026
Correlated noise is a critical failure mode in quantum error correction (QEC), as temporal memory and spatial structure concentrate faults into error bursts that undermine standard threshold assumptions. Yet, a fundamental gap persists between the st...
Optimal Decoding with the Worm
Zac Tobias, Nikolas P. Breuckmann, Benedikt Placke·Mar 5, 2026
We propose a new decoder for "matchable'' qLDPC codes that uses a Markov Chain Monte Carlo algorithm - called the worm algorithm - to approximately compute the probabilities of logical error classes given a syndrome. The algorithm hence performs (app...
Achieving Thresholds via Standalone Belief Propagation on Surface Codes
Pedro Hack, Luca Menti, Francisco Lazaro +1 more·Mar 5, 2026
The usual belief propagation (BP) decoders are, in general, exchanging local information on the Tanner graph of the quantum error-correcting (QEC) code and, in particular, are known to not have a threshold for the surface code. We propose novel BP de...