Eat Your Quantamins

Morning arXiv Digest (2026-05-17) Selected papers • Nothing particularly interesting today.

Morning arXiv Digest (2026-05-16) Selected papers • Linear-Time T-Gate Optimization via Random Abstraction (arXiv:2605.13929) • Takeaway: A randomized phase-folding analysis gives linear-time T-count optimization and scales to million-gate circuits while matching existing reductions. • Why JK should care: This is directly relevant to fault-tolerant compiling as resource suppression, and the randomized-abstraction angle may connect to circuit-level error/compression themes. • C-Phase-Aware Compilation for Efficient Fault-Tolerant Quantum Execution (arXiv:2605.14042) • Takeaway: The paper exploits C-Phase commutativity plus event-driven lattice-surgery scheduling to expose concurrency and reports up to 59.7× execution-time reduction. • Why JK should care: It is a concrete example where algebraic gate structure changes time/resource overhead, close to JK’s interest in symmetry-aware compiling constraints. • Worst-Case Sample Complexity Bounds for Distributed Inner Product Estimation with Local Randomized Measurements (arXiv:2605.14256) • Takeaway: It proves worst-case sample-complexity bounds for local randomized measurement inner-product estimation using Clifford commutants and local twirling identities. • Why JK should care: The local Clifford/twirling machinery is structurally adjacent to randomized compiling, shadow protocols, and rigorous bounds on what local randomization buys. • Multiple-Bases Belief Propagation List Decoding for Quantum LDPC Codes (arXiv:2605.14170) • Takeaway: A multiple-bases BP list decoder runs BP over redundant cycle-free parity-check views and improves QLDPC decoding performance without super-linear post-processing. • Why JK should care: It is not control theory, but it gives a practical noise-suppression mechanism where graph structure and redundancy matter quantitatively. • Univariate Bicycle Quantum LDPC Codes: Explicit Logical Structure and Distance Bounds (arXiv:2605.14173) • Takeaway: The authors define a Frobenius-restricted bicycle-code family with explicit logical coset parametrization and distance bounds from circulant cycle-density structure. • Why JK should care: The algebraic structure/distance-bound angle is useful background for fault-tolerance architectures that set the target constraints for control and compiling. • Universal quantum resource distillation via composite generalised quantum Stein's lemma (arXiv:2605.15174) • Takeaway: It shows universal optimal-rate resource distillation under resource non-generating operations without knowing the input state, via a composite quantum Stein lemma. • Why JK should care: The robustness-to-unknown-input formulation is conceptually close to robust quantum information processing, even if the paper lives in asymptotic resource theory. • Sharp Bounds on the Eigenvalues of Kikuchi Graphs and Applications to Quantum Max Cut (arXiv:2605.14994) • Takeaway: Sharp eigenvalue bounds for Kikuchi graph Laplacians imply improved approximation guarantees for Quantum Max Cut and the XY Hamiltonian. • Why JK should care: This is a clean QIP-style bounds paper with Hamiltonian/complexity flavor, good for tracking rigorous resource and approximation lower/upper-bound techniques.

Morning arXiv Digest (2026-05-15) Selected papers • Affiliated operators for classical and quantum control (arXiv:2605.13774) • Takeaway: Builds a von-Neumann-algebra framework for controllability of bilinear systems on infinite-dimensional Hilbert spaces, including existence of time-optimal controls and approximate-controllability tests for unbounded operators. • Why JK should care: This is unusually close to JK's geometry/control-complexity axis and may offer operator-algebra language for rigorous control-time and controllability barriers. • Optimal Bounds, Barriers, and Extensions for Non-Hermitian Bivariate Quantum Signal Processing (arXiv:2605.12656) • Takeaway: Proves tight anti-Hermitian query complexity bounds for non-Hermitian bivariate QSP, rules out a fast-forwarding regime in the bivariate polynomial model, and analyzes angle-finding landscape issues. • Why JK should care: Strong lower-bound/barrier content for Hamiltonian simulation/QSP, with the kind of asymptotic obstruction structure useful for robust-control complexity thinking. • Quantum state isomorphism problems for groups (arXiv:2605.12615) • Takeaway: Studies the complexity of deciding whether circuit-prepared quantum states are related by a group action, proving broad BQP-hardness and containment results with refinements for abelian, Clifford, and other groups. • Why JK should care: Group-action structure plus complexity classification intersects JK's symmetry-centered QIP interests and may be relevant to orbit-averaging/randomized-compiling formalisms. • Coherent control of spinmons (arXiv:2605.12588) • Takeaway: Proposes spinmons—transmons entangled with trapped Andreev quasiparticle spin—and develops electrostatic-gate and AC-flux routes for full coherent control while estimating noise robustness. • Why JK should care: A concrete device-level control/noise tradeoff paper, useful for connecting abstract robust-control ideas to superconducting-qubit architecture variants. • Quantum Precoded Polar Codes (arXiv:2605.12796) • Takeaway: Introduces CSS quantum codes from rate-1 precoded polar codes and reports short-block codes with logical error rates comparable to a much larger surface code over depolarizing noise. • Why JK should care: Potentially interesting for error-suppression architecture and finite-block noise-tailoring intuition, even if it is more coding-theory than control. • QuPort: Topology-, Port-, and Congestion-Aware Compilation for Modular Multi-QPU Quantum Systems (arXiv:2605.12583) • Takeaway: Presents a modular-QPU compiler model optimizing logical interaction cuts, port overflow, and interconnect congestion rather than treating mapping as a single-device connectivity problem. • Why JK should care: Modular compilation constraints are a natural playground for resource lower bounds and physically constrained randomized/robust circuit design. • Physics Guided Generative Optimization for Trotter Suzuki Decomposition (arXiv:2605.13268) • Takeaway: Uses a diffusion-model generate-and-evaluate loop with PINN fidelity feedback and commutator-structure GNNs to optimize grouping, order, and timestep allocation in Trotter-Suzuki simulation. • Why JK should care: The physics-guided optimization of product formulas is adjacent to pulse/circuit co-design, though likely more heuristic than theorem-ready.

Morning arXiv Digest (2026-05-14) Selected papers • Joint Realizability Tradeoffs Bounded by Quantum Channel Incompatibility (arXiv:2605.11924) • Takeaway: Generalized robustness of channel incompatibility lower-bounds the total error of any approximate joint realization, unifying measurement uncertainty, information-disturbance, no-cloning, and no-broadcasting tradeoffs. • Why JK should care: This is a clean resource-theoretic lower-bound paper on unavoidable error tradeoffs in quantum channels, very close to JK’s robustness/geometry/bounds axis. • Simulation of Non-Hermitian Hamiltonians with Bivariate Quantum Signal Processing (arXiv:2605.12450) • Takeaway: The paper gives query-optimal simulation of dissipative/non-Hermitian Hamiltonians via bivariate QSP with non-commuting signal operators and matching lower bounds in a separate-oracle model. • Why JK should care: It is a strong QIP-algorithmic result with explicit complexity bounds and a potentially useful template for controlled open-system simulation primitives. • Scalable linearized gate set tomography (arXiv:2605.11158) • Takeaway: Linearized GST combines sparse error models, shallow circuits, and linearized fitting to scale characterization of coherent and stochastic multi-qubit errors beyond standard GST. • Why JK should care: It targets precisely the coherent-error/crosstalk diagnosis layer that robust control and circuit-level suppression schemes need to be credible experimentally. • Zeno-Enhanced Probabilistic Error Cancellation with Quantum Error Detection Codes (arXiv:2605.12149) • Takeaway: Post-selected quantum error detection is used to compress physical noise into a weaker accepted logical channel before applying PEC only to the residual noise. • Why JK should care: This is directly in the coherent error mitigation/error-detection hybrid zone, with useful structure for thinking about overhead reduction by symmetry/post-selection constraints. • Quantum Fanout Gates in Constant Depth via Resonance Engineering (arXiv:2605.11073) • Takeaway: A resonance-engineered Jaynes-Cummings interaction with a common oscillator realizes an n-qubit fanout gate in constant time with analytically bounded, linearly scaling infidelity. • Why JK should care: Constant-depth fanout and faster stabilizer readout touch both hardware-aware control design and circuit-depth lower-bound/escape-hatch questions. • Lower overhead fault-tolerant building blocks for noisy quantum computers (arXiv:2605.12385) • Takeaway: The authors redesign core fault-tolerant building blocks to reduce spacetime overhead for error-corrected computation. • Why JK should care: Even if more engineering-facing, the paper may contain concrete overhead tradeoffs and stabilizer-measurement primitives relevant to error-suppression architecture choices. • Runtime Calibration as State-Trajectory Feedback Control in Quantum-Classical Workflows (arXiv:2605.11860) • Takeaway: Runtime calibration is formulated as a finite-horizon feedback-control problem where calibration actions reset a drifting quality state under a wall-clock budget. • Why JK should care: The control framing is conceptually neat for turning calibration scheduling into an optimal-control problem rather than a static compiler heuristic.

Morning arXiv Digest (2026-05-13) Selected papers • Crystallographic Symmetry Generates Phononic Holonomic Gates with Biased-Erasure Channels (arXiv:2605.10932) • Takeaway: Crystallographic symmetry is used to make strain-driven holonomic gates whose error channels are naturally biased-erasure-like. • Why JK should care: This is close to JK's symmetry/control/error-geometry axis: a concrete hardware-control layer where symmetry dictates both gate structure and decoder-legible noise. • A passive self-correcting quantum memory in three dimensions (arXiv:2605.10943) • Takeaway: The paper constructs a 3D Pauli stabilizer Hamiltonian claimed to encode a qubit for exponential time at nonzero temperature while retaining geometric locality. • Why JK should care: If the construction is sound, it is a serious error-suppression/QEC architecture result and a useful benchmark for robustness-vs-resource thinking. • On the KAK Decomposition and Equivalence Classes (arXiv:2605.10783) • Takeaway: The authors give a more careful mathematical treatment of KAK decompositions and equivalence classes for compact semisimple groups, including SU(4). • Why JK should care: KAK/SU(4) structure sits directly under two-qubit gate geometry, local-equivalence classes, and control-compilation normal forms. • Equivariant Reinforcement Learning for Clifford Quantum Circuit Synthesis (arXiv:2605.10910) • Takeaway: A qubit-permutation-equivariant RL architecture learns Clifford circuit synthesis policies from symplectic representations and generalizes across system sizes. • Why JK should care: The symmetry-aware synthesis angle is relevant to randomized compiling/orbit methods, even if the ML layer is more engineering than theorem. • On Scalable Pseudorandom Unitaries and the Unitary Synthesis Problem (arXiv:2605.09957) • Takeaway: The paper links scalable pseudorandom unitary constructions to the Aaronson-Kuperberg unitary synthesis problem via ROM-style PRU analysis. • Why JK should care: It touches unitary synthesis, complexity barriers, and what it means for families of unitaries to be efficiently implementable or pseudorandom. • On the Simulation Cost of Quantum Finite Automata (arXiv:2605.10682) • Takeaway: The paper gives sharp exact probabilistic simulation costs for representative quantum finite automata models under strict cutpoints. • Why JK should care: It is a clean finite-dimensional example of quantum-vs-classical simulation overhead, useful for complexity intuition even outside control. • Multi-Prover Interactive Proof Systems with Leakage (arXiv:2605.09872) • Takeaway: The work studies how bounded communication/leakage between provers affects the power of multi-prover interactive proof systems. • Why JK should care: This is squarely QIP-style complexity and may be worth tracking for structural results on entanglement, nonlocality, and proof-system robustness.

Morning arXiv Digest (2026-05-12) Selected papers • Mid-Circuit Measurements for Clifford Noise Reduction in Hamiltonian Simulations (arXiv:2605.06792) • Takeaway: Encoded Hamiltonian simulation with symplectic-transvection Trotter synthesis, Clifford noise reduction, and mid-circuit stabilizer checks cuts logical error by up to 54% on an ion-trap-style benchmark. • Why JK should care: This is a concrete pulse/circuit-level error-suppression mechanism where timing of syndrome information, not just encoding, is the decisive resource. • Computational and physical complexity of synthesizing random multi-qudit quantum states and unitary operators (arXiv:2605.07374) • Takeaway: The paper compares gate-count complexity with minimum-time optimal-control complexity for random multi-qudit states and unitaries, finding evidence that physical control complexity can scale more gently than circuit complexity. • Why JK should care: This sits directly on JK's robust/control-complexity axis: when does continuous control beat gate synthesis, and what lower-bound notion is actually physical? • Bridging Krylov Complexity and Universal Analog Quantum Simulator (arXiv:2605.07668) • Takeaway: Generalized Krylov complexity is proposed as a predictor of the minimum control time needed to synthesize target operations in globally controlled analog quantum simulators. • Why JK should care: It offers a candidate geometric/operator-growth diagnostic for control difficulty, close to the kind of structural complexity measure JK keeps trying to formalize. • Symplectic H2 Model Reduction for High-Dimensional Linear Quantum Systems (arXiv:2605.07152) • Takeaway: A symplectic Petrov-Galerkin / Quantum IRKA method reduces large linear quantum systems while preserving physical realizability and canonical commutation structure to machine precision. • Why JK should care: Structure-preserving reduction is useful machinery for making high-dimensional open/control systems analyzable without destroying the physics. • Hardware-Free Polarization Stabilization for Measurement-Device-Independent Quantum Key Distribution via Correlated Twirling (arXiv:2605.07229) • Takeaway: A synchronized virtual correlated-twirling protocol converts asymmetric polarization drift into an effectively isotropic Pauli depolarizing channel in MDI-QKD post-processing. • Why JK should care: Even if the application is QKD, the symmetry move is very JK-shaped: use twirling/orbits to turn coherent geometric misalignment into a benign stochastic channel. • Quantitative propagation of chaos for Lindblad dynamics (arXiv:2605.06973) • Takeaway: The paper proves explicit order-1/N relative-entropy convergence bounds from N-body Lindblad dynamics to the nonlinear mean-field limit. • Why JK should care: It is a clean open-system theorem with quantitative bounds, potentially useful background for noise-averaging and many-body dissipative control arguments. • Systematic frequency-collision analysis of the cross-resonance gate outside the straddling regime (arXiv:2605.07868) • Takeaway: Far-detuned cross-resonance designs are numerically shown to reduce frequency collisions, with linear-programmed frequency allocation and yield estimates for large transmon lattices. • Why JK should care: This is hardware-engineering rather than theory, but it gives concrete constraints for robust gate design under frequency-crowding noise.

Morning arXiv Digest (2026-05-11) Selected papers • Mid-Circuit Measurements for Clifford Noise Reduction in Hamiltonian Simulations (arXiv:2605.06792) • Takeaway: Combines GSE Trotter synthesis, Clifford Noise Reduction, and Shor-style stabilizer checks with mid-circuit measurements to suppress accumulated noise in encoded fermionic Hamiltonian simulations. • Why JK should care: This is directly in the noise-robust simulation/control stack and looks like a concrete mitigation recipe rather than another decorative NISQ fern. • Systematic frequency-collision analysis of the cross-resonance gate outside the straddling regime (arXiv:2605.07868) • Takeaway: Analyzes operating cross-resonance gates in a far-detuned regime to ease frequency crowding in fixed-frequency transmon processors. • Why JK should care: Frequency-collision-aware gate design is squarely relevant to scalable compiling and control constraints for superconducting hardware. • Price and Payoff: Non-Determinism in Fault Tolerant Quantum Computation (arXiv:2605.07983) • Takeaway: Studies how nondeterministic magic-state production affects the space-time resource tradeoffs of fault-tolerant quantum computation. • Why JK should care: It connects architectural resource allocation to realistic stochastic behavior, which matters for robust compilation cost models. • Error Correction of Beamsplitter-Generated Entangled GKP States (arXiv:2605.08009) • Takeaway: Investigates error correction for entangled GKP states produced by beamsplitter interactions, a fault-tolerant primitive in bosonic codes. • Why JK should care: Bosonic error-correction primitives are a clean place to think about hardware-native gates, noise structure, and code-compatible controls. • Generalized master equation for driven quantum oscillators: microscopic origin of nonlinear dissipation and asymmetric resonances (arXiv:2605.08021) • Takeaway: Derives a generalized Caldeira-Leggett master equation retaining nonlinear and time-dependent driven oscillator dynamics in the dissipator. • Why JK should care: Better microscopic dissipators for driven nonlinear systems can sharpen control/noise models beyond vanilla Lindblad assumptions. • Loop Composition in Quantum Algorithms (arXiv:2605.07518) • Takeaway: Uses a quantum-walk formalism to compose different-length quantum subroutines in superposition, yielding improved variable-time-style algorithmic composition. • Why JK should care: This is a QIP-theory paper with potential implications for algorithmic primitives and complexity-aware circuit construction. • Computational and physical complexity of synthesizing random multi-qudit quantum states and unitary operators (arXiv:2605.07374) • Takeaway: Compares gate-count computational complexity with physical-control complexity for synthesizing random multi-qudit states and unitaries. • Why JK should care: The computational-vs-physical complexity split is useful language for thinking about what pulse/control access buys over abstract circuits.

Morning arXiv Digest (2026-05-02) Selected papers • g-tensor Optimization in Ge/SiGe Quantum Dots (arXiv:2604.28081) • Takeaway: This paper gives a concrete optimization framework for engineering Ge/SiGe hole-spin qubit g-tensors, including heterostructure reshaping that suppresses unwanted in-plane components. • Why JK should care: It is directly about making qubit control more predictable and robust by design, which is exactly the kind of device-level control leverage you like. • Heisenberg-limited Hamiltonian learning without short-time control (arXiv:2604.27838) • Takeaway: The authors show you can keep optimal 1/ε Hamiltonian-learning scaling even when experiments cannot access arbitrarily short-time evolutions. • Why JK should care: That closes a painful theory-to-lab gap caused by finite bandwidth and pulse transients, so it is highly relevant to realistic characterization and control. • Parametrically Driven iSWAP Gate Using a Capacitively Shunted Double-Transmon Coupler at the Zero-Flux Sweet Spot (arXiv:2604.27679) • Takeaway: They demonstrate a 112 ns zero-flux-bias parametrically driven iSWAP with 99.92% average fidelity using a simple waveform and low effective ZZ. • Why JK should care: Sweet-spot operation plus simpler pulse requirements is exactly the sort of practical robustness win that matters for scalable control stacks. • Branch-Resolved Characterization of Feed-Forward Error in Dynamic Teleportation via Classical Choi Shadows (arXiv:2604.28037) • Takeaway: This work introduces a branch-resolved framework to diagnose measurement-conditioned feed-forward errors in dynamic teleportation, and validates it experimentally. • Why JK should care: It offers a cleaner way to localize dynamic-circuit error mechanisms instead of hiding them inside branch-averaged metrics. • Learning quantum disentanglement scheduling from reduced states via modular hybrid policies (arXiv:2604.28009) • Takeaway: The paper studies reduced-information quantum control and shows which hybrid quantum-classical policy ingredients actually matter for disentanglement scheduling. • Why JK should care: Even if the RL layer is not the main attraction, the reduced-state control framing is very close to realistic closed-loop control constraints. • Effective Noise Mitigation via Quantum Circuit Learning in Quantum Simulation of Integrable Spin Chains (arXiv:2604.27648) • Takeaway: The authors use shallow learned circuits to mimic deeper dynamics while preserving conserved quantities better than the noisy original circuits. • Why JK should care: It is a nice physics-informed error-suppression angle, especially because it trades depth for robustness without exponential mitigation overhead. • Unentangled stoquastic Merlin-Arthur proof systems: the power of unentanglement without destructive interference (arXiv:2604.27886) • Takeaway: This paper opens up the complexity class StoqMA(2) and shows surprisingly strong upper and lower bounds for unentangled stoquastic proof systems. • Why JK should care: It is the cleanest QIP-style theory pick today, with real complexity-content rather than generic quantum-algorithms fluff.

Morning arXiv Digest (2026-05-01) Selected papers • HyPulse: A Pulse Synthesis Framework for Hybrid Qubit-Oscillator Gates on Trapped-Ion Platform (arXiv:2604.26804) • Takeaway: HyPulse introduces a hardware-aware two-phase pipeline that caches high-fidelity pulse primitives and assembles parameterized trapped-ion hybrid gates on demand. • Why JK should care: It directly targets pulse-level compilation bottlenecks for continuously parameterized control gates, which maps tightly to robust control and pulse design work. • Arbitrary parallel entangling gates with independent calibration on a trapped ion quantum computer (arXiv:2604.25993) • Takeaway: The paper demonstrates parallel entangling gates with near single-pair fidelity and near linear speedup for disjoint pairs on trapped-ion hardware. • Why JK should care: Parallel calibrated entangling operations are a practical route to lower-depth circuits and reduced accumulated error in near-term devices. • Tikhonov-regularised projected gradient flow for equality-constrained bilinear quantum control (arXiv:2604.26625) • Takeaway: A regularized projected-gradient control method is given with stability guarantees, monotonic objective ascent, and explicit discretization criteria. • Why JK should care: It offers mathematically grounded fixes for ill-conditioning and step instability in constrained quantum optimal control workflows. • Strict Hierarchy for Quantum Channel Certification to Unitary (arXiv:2604.26900) • Takeaway: The authors establish tight query complexities across incoherent, coherent, and source-code access models, proving a strict hierarchy for unitary-channel certification. • Why JK should care: This sharpens complexity limits for verification-style primitives that matter when benchmarking robust compiled/control pipelines. • En Route to a Standard QMA1 vs. QCMA Oracle Separation (arXiv:2604.26921) • Takeaway: The work provides new oracle separations around QMA1 versus QCMA, including bounded-adaptivity and small-gap regimes. • Why JK should care: It is a strong QIP-theory update on witness power and adaptivity, aligned with JK's complexity-and-bounds interest slice. • Cavity-mediated coherence protection and one-axis twisting for spins in solids (arXiv:2604.26909) • Takeaway: Experiments in a solid-state spin ensemble show cavity-mediated interactions that both generate one-axis twisting and extend Ramsey coherence by opening a protective many-body gap. • Why JK should care: It is a concrete coherence-protection mechanism relevant to error suppression and robust operation in realistic noisy platforms. • Practical Insights into Fair Comparison and Evaluation Frame for Neutral-Atom Compilers (arXiv:2604.25478) • Takeaway: A reproducible RSQASM-based framework reveals that several claimed neutral-atom compiler gaps shrink after enforcing fair, equivalent evaluation assumptions. • Why JK should care: Better compiler evaluation hygiene helps avoid overclaiming gains and improves decision quality for compilation strategies in noisy hardware settings.

Morning arXiv Digest (2026-04-30) Selected papers • Data-Driven Hamiltonian Reduction for Superconducting Qubits via Meta-Learning (arXiv:2604.24912) • Takeaway: A meta-learning pipeline infers effective two-qubit Hamiltonians from a few measurements, staying accurate even where perturbative reductions break down. • Why JK should care: This is directly about fast characterization and control-model adaptation for superconducting qubits, which sits right in your calibration and pulse-design lane. • Pulse Quality Optimisation in Quantum Optimal Control (arXiv:2604.25768) • Takeaway: GECKO improves already-good control pulses by moving along fidelity-preserving directions to optimize smoothness, robustness, filtering, or duration. • Why JK should care: It is a clean control-theory idea for turning "works in simulation" pulses into hardware-friendlier ones without redoing the whole optimization. • Proof of the Error Scaling for Universally Robust Dynamical Decoupling Sequences (arXiv:2604.25807) • Takeaway: This gives a rigorous proof that even-order URn dynamical decoupling sequences achieve the claimed n-th order suppression of pulse errors. • Why JK should care: It strengthens the theoretical footing of a practical robustness tool for suppressing control imperfections and environmental noise. • Stabilizers for Compiling Logical Circuits under Hardware Constraints (arXiv:2604.25042) • Takeaway: The paper uses code redundancy to choose logically equivalent but hardware-native implementations, reducing compilation pain such as extra SWAPs. • Why JK should care: It connects fault tolerance and compilation in a way that could matter for constrained-connectivity architectures and logical-circuit design. • MCMit: Mid-Circuit Measurement Error Mitigation (arXiv:2604.25863) • Takeaway: A hardware-software co-design cuts feedback latency and improves mid-circuit measurement discrimination, yielding lower logical error rates in dynamic circuits. • Why JK should care: Mid-circuit measurement is a real bottleneck for QEC and adaptive control workflows, so this is relevant to practical noise robustness. • Defect-Adaptive Lattice Surgery on Irregular Boundary Surface-Code Patches (arXiv:2604.25524) • Takeaway: The authors give a synthesis layer for executing lattice-surgery parity measurements on defect-deformed surface-code patches. • Why JK should care: It is a useful step from idealized QEC layouts toward actually compiling fault-tolerant operations on imperfect hardware. • Universal Characterization of Classical Qubit Noise (arXiv:2604.25705) • Takeaway: Repetitive Ramsey interferometry is used as a general protocol to recover arbitrary-order correlation functions of classical dephasing noise. • Why JK should care: Better noise spectroscopy feeds directly into robust control design, model validation, and deciding what kind of suppression strategy is worth trying.

Morning arXiv Digest (2026-04-29) Selected papers • DiffQEC: A versatile diffusion model for quantum error correction (arXiv:2604.24640) • Takeaway: A diffusion-based generative decoder uses full syndrome histories to model the posterior over errors and beats MWPM by up to 10.2% on Google experimental data. • Why JK should care: This is a concrete noise-robustness result with real-device evidence, and the posterior-view of decoding may suggest new hybrid control-and-decoding ideas. • CAbLECAR: efficiently scheduling QLDPC codes on a tileable spin qubit chip with shuttling (arXiv:2604.24739) • Takeaway: The paper builds a coordinated shuttle scheduling algorithm for shuttling-based spin qubit hardware and reports up to 86% faster schedules with strong logical-performance gains for selected QLDPC codes. • Why JK should care: It sits right at the control-compilation-hardware interface, where scheduling under a realistic noise model materially changes fault-tolerance prospects. • Gate-dependent offset charge shifts and anharmonicity in gatemon qubits in the weak tunneling regime (arXiv:2604.24716) • Takeaway: A many-body effective model predicts gate-dependent charge offsets and capacitance renormalization in gatemons, with an explicit protocol to detect the effect experimentally. • Why JK should care: It is a sharp device-level control paper about how tuning knobs reshape the qubit Hamiltonian and therefore the usable control landscape. • Singlet-triplet oscillations in multivalley Si double quantum dots (arXiv:2604.24689) • Takeaway: The authors derive a spin-valley theory for charge separation and singlet-triplet mixing that explains oscillation renormalization and dephasing near spin-valley resonances. • Why JK should care: It connects noise, valley physics, and control/readout calibration in silicon spin qubits, which is exactly the kind of hidden-structure robustness issue that bites later. • Optimization Using Locally-Quantum Decoders (arXiv:2604.24633) • Takeaway: The paper proposes an intrinsically quantum decoder for LDPC-style encodings of optimization problems and shows clear gains over belief propagation, though not an actual quantum advantage. • Why JK should care: It is a neat QIP-style bridge between decoding, optimization, and lower-bound thinking, with a refreshingly honest 'almost but not quite' conclusion. • Constructive Separations from Gate Elimination (arXiv:2604.23958) • Takeaway: Gate-elimination lower bounds are recast as explicit refutation algorithms that can efficiently find counterexamples for undersized circuits, including affine-disperser bounds. • Why JK should care: This is strong complexity-side food, especially if you care about when lower-bound proofs can be made algorithmically constructive rather than merely existential.

Morning arXiv Digest (2026-04-28) Selected papers • Boundary-Aware Stabilizer Scheduling for Distributed Quantum Error Correction (arXiv:2604.22471) • Takeaway: This paper proposes boundary-aware stabilizer scheduling for modular topological QEC, aiming to reduce coordination overhead and improve fault-tolerant operation across linked QPUs. • Why JK should care: It is directly about making error-correction schedules more architecture-aware, which is close to JK's interest in robustness under realistic hardware constraints. • Analytical and Compressed Simulation of Noisy Stabilizer Circuits (arXiv:2604.22588) • Takeaway: The authors derive efficient analytical and algorithmic methods for simulating a broad class of noisy stabilizer circuits without paying the full generic noise-simulation cost. • Why JK should care: Better noisy-circuit simulation is useful for quickly stress-testing error-suppression ideas and compiler/control heuristics before hardware deployment. • A four-player potential game for barren-plateau-aware quantum ansatz design (arXiv:2604.21955) • Takeaway: The paper frames variational ansatz design as a multi-objective game balancing trainability, expressivity, task performance, and hardware cost, explicitly targeting barren plateaus. • Why JK should care: It is a neat control-and-compilation adjacent take on co-designing circuits for trainability and hardware realism rather than raw expressivity alone. • Quantum Circuit Partitioning For Effective Utilization of Quantum Resources (arXiv:2604.22664) • Takeaway: This work studies partitioning larger circuits into resource-feasible pieces to improve execution on noisy, capacity-limited near-term hardware. • Why JK should care: Circuit partitioning is relevant to compiling under hardware limits, especially when robustness depends as much on layout and decomposition as on the original algorithm. • Entanglement Enhanced Sensing with Qubits affected by non-Markovian Dephasing (arXiv:2604.22368) • Takeaway: The paper analyzes how entanglement-assisted sensing performance changes once realistic non-Markovian dephasing is included. • Why JK should care: Even though it is framed as sensing, the treatment of structured dephasing noise is directly relevant to thinking about noise robustness beyond simple Markovian models. • The Exact Replica Threshold for Nonlinear Moments of Quantum States (arXiv:2604.22627) • Takeaway: The authors identify the sharp replica threshold governing when joint measurements on multiple state copies unlock nonlinear observables efficiently. • Why JK should care: This is the most QIP-style pick today, with a clean complexity-flavored threshold result that may be intellectually useful even if it is less immediately hardware-facing.