quant-ph digest — 2026-05-18
Scored against Yuan's research programme (Y1–Y6):
- Y1 — arXiv:2502.09704 — iterative warm-started QAOA
- Y2 — arXiv:2304.06915 — quasi-binary portfolio QAOA
- Y3 — arXiv:2410.16265 — QAOA DGMVP portfolio (QST 2026)
- Y4 — arXiv:2603.14744 — Grover + ADMM cardinality-constrained BO
- Y5 — arXiv:2510.08292 — GW speed-ups via Gibbs states + Pauli sparsity
- Y6 — arXiv:2510.11213 — PBR test on IBM Heron2
Source
arXiv listing: https://arxiv.org/list/quant-ph/new (59 new + 19 cross = 78 entries; announce cycle Friday 15 May 2026)
Coverage: all 78 entries scored. 15 relevant (score ≥ 1); 63 SKIP (score 0, omitted).
Scoring rubric
0–10 on method/scope/conclusion overlap — max wins. HIGH 8–10 · MED 5–7 · LOW 1–4 · SKIP 0.
Highly relevant (score 8–10) — 1 paper
Sharp Bounds on the Eigenvalues of Kikuchi Graphs and Applications to Quantum Max Cut
- Authors: Ainesh Bakshi, Arpon Basu, Pravesh Kothari, Anqi Li
- arXiv: 2605.14994
- Category: new submission — Quantum Physics (quant-ph); Data Structures and Algorithms (cs.DS); Combinatorics (math.CO)
- Score: 8/10 (HIGH)
- Overlaps with: Y5 (method + scope — approximation algorithms for graph Hamiltonians, alternative spectral route to GW-style relaxations) and Y1 (scope — MaxCut family / approximation-ratio benchmark)
- Why it matters: Resolves the Apte–Parekh–Sud spectral conjectures on Kikuchi/token graphs and pushes the worst-case approximation ratio for Quantum Max Cut from 0.611 to 0.614 (and XY from prior best to 0.674) with efficient algorithms outputting tensor products of one- and two-qubit states. This is the new classical baseline any quantum or quantum-inspired QMC approximator must beat.
We prove that the maximum eigenvalue of the (both signed and unsigned) Laplacian of level k Kikuchi graph of any graph G with m edges is at most m+k. This confirms four recent conjectures of Apte, Parekh, and Sud. As applications, we obtain that tensor products of one and two qubit product states achieve an approximation ratio of 5/8 for Quantum Max Cut and 5/7 for the XY Hamiltonian. Moreover, combining our bounds with the algorithms analyzed by Apte, Parekh, and Sud, yields efficient algorithms achieving an approximation ratio of 0.614 for Quantum Max Cut and 0.674 for the XY Hamiltonian. Finally, we also make modest progress on Brouwer's conjecture and improve Lew's bound on the sum of the top-k eigenvalues of a Graph Laplacian.
Moderately relevant (score 5–7) — 9 papers
Winning Lottery Tickets in Neural Networks via a Quantum-Inspired Classical Algorithm
- Authors: Natsuto Isogai, Hayata Yamasaki, Sho Sonoda, Mio Murao
- arXiv: 2605.13979
- Category: new submission — Quantum Physics (quant-ph); Machine Learning (cs.LG); Machine Learning (stat.ML)
- Score: 7/10 (MED)
- Overlaps with: Y5 (method — dequantisation of a QML primitive, replacing exponential-time classical baseline with poly-time)
- Why it matters: Constructs a fully classical poly-time algorithm matching a known QML algorithm's
O(D)sampling claim, removing the exponential dependence on data dimension. Directly mirrors Y5's pattern of quantum-inspired classical algorithms competing with the quantum primitive — useful comparison point for the next iteration of Pauli-sparse dequantisation.
Quantum machine learning (QML) aims to accelerate machine learning tasks by exploiting quantum computation. Previous work studied a QML algorithm for selecting sparse subnetworks from large shallow neural networks. […] The quantum algorithm performs this sampling in time O(D) in the data dimension D, whereas a naive classical implementation relies on handling exponentially many candidate nodes and hence takes exp[O(D)] time. In this work, we construct and analyze a quantum-inspired fully classical algorithm for the same sampling task. We show that our algorithm runs in time O(poly(D)), thereby removing the exponential dependence on D from the previous classical approach.
QUACOD: Quantum Optimization via Coordinate Descent for Scalable Drone Scheduling
- Authors: Van-Quang-Huy Nguyen, Hoang-Quan Nguyen, Samee U. Khan, Ilya Safro, Khoa Luu
- arXiv: 2605.14001
- Category: new submission — Quantum Physics (quant-ph)
- Score: 6/10 (MED)
- Overlaps with: Y4 (method — classical-quantum decomposition under qubit budget), Y2/Y3 (scope — constrained combinatorial optimisation on NISQ hardware)
- Why it matters: A coordinate-descent decomposition that splits a large constrained optimisation into qubit-budget-feasible subproblems, then solves each with a hardware-efficient circuit. Sits in the same ADMM-style classical-quantum hybrid space as Y4 but uses block coordinate descent instead of dual decomposition — worth contrasting against Y4's approximation guarantees.
Quantum computing has demonstrated its potential to solve various optimization problems, including drone scheduling […]. However, one of the main obstacles is that practical drone scheduling settings typically require quantum resources that current hardware cannot provide. […] We introduce a new Quantum Optimization via Coordinate Descent (QUACOD) approach to address this problem under the constraint of a limited number of available qubits. By leveraging coordinate descent, QUACOD decomposes the original high-complexity problem into multiple subproblems, which are then solved using quantum optimization.
Failure-Guided Fuzzing for Hybrid Quantum-Classical Programs
- Authors: Lei Zhang
- arXiv: 2605.14219
- Category: cross submission — Software Engineering (cs.SE); Quantum Physics (quant-ph)
- Score: 6/10 (MED)
- Overlaps with: Y1, Y3 (scope — VQE and QAOA-MaxCut test targets in Qiskit; relevant to the QAOA stack used in Y1's iterative warm-started experiments)
- Why it matters: Tooling paper — but the case studies are a QAOA-MaxCut instance and a VQE instance in Qiskit, with explicit modelling of failure-prone regions in joint (optimizer × circuit-parameter) space. Useful if you ever want a systematic way to stress-test the iterative warm-started QAOA stack for non-convergent parameter regions.
Hybrid quantum-classical (HQC) algorithms, such as the Variational Quantum Eigensolver (VQE) and the Quantum Approximate Optimization Algorithm (QAOA), are central to near-term quantum computing but remain challenging to test. Sampling-based fuzzing can expose faulty or non-convergent configurations, but under realistic execution budgets, it may miss failure-prone regions in the joint space of classical optimizer settings and quantum circuit parameters. This paper studies failure-guided fuzzing for HQC programs. It models a hybrid input as a pair of classical optimizer hyperparameters and quantum circuit parameters, and evaluates a two-phase strategy that first searches for non-convergent seeds and then locally fuzzes circuit parameters around those seeds.
Optimizing the preparation of Dicke states using counterdiabatic driving methods
- Authors: Fengzhe Tang, Gangcheng Wang
- arXiv: 2605.14378
- Category: new submission — Quantum Physics (quant-ph)
- Score: 6/10 (MED)
- Overlaps with: Y2, Y4 (scope — Dicke states are the canonical fixed-Hamming-weight initial state for cardinality-preserving QAOA mixers and for Grover search over fixed-cardinality subspaces)
- Why it matters: Counterdiabatic-driven Dicke-state preparation directly produces the initial state needed by the hard-mixer / fixed-cardinality QAOA used in Y2 (quasi-binary portfolio) and by Y4's Grover search over
C(n,k)-sized feasible spaces. A high-fidelity, faster prep recipe lowers the depth budget for both lines.
Recently, the technique of counterdiabatic driving […] has been widely applied in the preparation of many-body quantum states. In this work, we propose a theoretical scheme for the efficient preparation of Dicke states in a system of non-interacting two-level atoms. Our approach leverages the one-axis twisting (OAT) interaction to generate non-classical correlations and combines it with time-dependent external fields to achieve precise control over the dynamics of the system. […] To further optimize the preparation process, we introduce counterdiabatic driving (CD), which suppresses non-adiabatic transitions.
Are free choices absolute, when internalized in Wigner's friend?
- Authors: Laurens Walleghem
- arXiv: 2605.14538
- Category: new submission — Quantum Physics (quant-ph)
- Score: 6/10 (MED)
- Overlaps with: Y6 (conclusion + scope — directly invokes the PBR theorem inside an extended Wigner's friend argument)
- Why it matters: Explicitly builds a no-go argument on the Pusey–Barrett–Rudolph theorem — same foundational object Y6 tested experimentally on Heron2. A natural companion citation when discussing what the experimental PBR violation says about absoluteness assumptions.
Wigner's thought experiment illustrates quantum theory's measurement problem by considering an observer who measures a quantum system inside a sealed lab, modeled unitarily by an outsider. Recent extensions of this thought experiment […] question how different observers can reason consistently about each other in quantum setups, and challenge the absoluteness of the outcome value obtained by the friend under a notion of locality. In this work, we present an argument against the absoluteness of free choices under the same notion of locality, using an extended Wigner's friend scenario based on the Pusey–Barrett–Rudolph theorem.
From Hilbert's Tenth Problem to Quantum Speedup: Explicit Oracles for Bounded Diophantine Systems
- Authors: Gabriel Escrig, M. A. Martin-Delgado
- arXiv: 2605.13980
- Category: new submission — Quantum Physics (quant-ph)
- Score: 5/10 (MED)
- Overlaps with: Y4 (method — explicit gate-level evaluation oracle for amplitude amplification over a discrete bounded feasible space)
- Why it matters: Constructs explicit reversible Toffoli-depth-bounded oracles for amplitude amplification over bounded-integer feasible sets — the same architectural pattern Y4 uses for Grover search over cardinality-constrained binary domains. The arithmetic-encoding tricks (in-place two's complement, recycled accumulator) may transfer.
Solving non-linear Diophantine systems lies at the mathematical core of integer optimization and cryptography. […] We introduce a fully reversible quantum algorithmic framework tailored to solve arbitrary polynomial Diophantine equations over bounded integer domains. The core of our approach is the explicit, gate-level synthesis of an evaluation oracle for amplitude amplification. By coherently evaluating polynomial constraints via in-place two's complement arithmetic and routing operations into a single recycled accumulator, this garbage-free strategy achieves a compact and scalable synthesis of the underlying non-linear arithmetic.
Interference visibility as a witness of preparation contextuality via overlap inequalities
- Authors: Mohd Asad Siddiqui
- arXiv: 2605.14395
- Category: new submission — Quantum Physics (quant-ph)
- Score: 5/10 (MED)
- Overlaps with: Y6 (scope — operational tests of preparation noncontextuality, sister framework to ontic-model tests like PBR)
- Why it matters: Derives tight overlap inequalities (cycle inequalities) for preparation noncontextuality from pairwise interference visibilities — an alternative operational handle on the same epistemic/ontic boundary Y6 probes. Useful comparison if you ever extend the Heron2 protocol to broader contextuality tests.
We show that standard multi-path interferometry, using only pairwise visibility measurements, provides an operational route to tests of preparation noncontextuality. Under ideal symmetric conditions, interference visibility directly encodes state overlaps, without requiring tomography or SWAP tests. […] We generalize to arbitrary n-path interferometers and derive the tight qubit bound Snmax = n cos2(π/2n) − 1 for all n ≥ 3, achieved by coplanar pure qubit states with uniform angular separation π/n. […] Under the operational equivalences used in overlap-based generalized noncontextuality frameworks, violations of these visibility inequalities also witness preparation contextuality.
Generating Non-Decomposable Maps with Differentiable Semidefinite Programming
- Authors: Angela Rosy Morgillo, Davide Poderini, Fabio Anselmi, Fabio Benatti, Massimiliano F. Sacchi, Chiara Macchiavello
- arXiv: 2605.14644
- Category: new submission — Quantum Physics (quant-ph)
- Score: 5/10 (MED)
- Overlaps with: Y5 (method — differentiable SDP optimisation, adjacent to Y5's structured GW relaxations)
- Why it matters: Pairs SDP certificates with gradient-based search over structured Choi matrices — a methodological cousin to Y5's structured GW relaxations. The differentiable-SDP framing is portable to other certificate-driven SDP problems including approximation-algorithm design.
Positive maps that are not decomposable are a key resource in entanglement theory because they can detect bound entangled states, yet systematic methods for constructing them remain limited. We introduce an optimization framework based on differentiable semidefinite programming (SDP) for generating positive non-decomposable maps under flexible structural constraints on their Choi matrices. The method combines SDP-based certificates of non-decomposability and positivity with gradient-based optimization, enabling a systematic search over maps with different input and output dimensions.
Nonlinear Hamiltonians and Boolean satisfiability
- Authors: Michael R. Geller, Victoria S. Ordonez, Yohannes Abate
- arXiv: 2605.14822
- Category: new submission — Quantum Physics (quant-ph)
- Score: 5/10 (MED)
- Overlaps with: Y4 (scope — counting / solving Boolean constraint problems with quantum oracles)
- Why it matters: Combines an FT quantum circuit evaluating a CNF formula with nonlinear-Hamiltonian discrimination on an ancilla to solve UNIQUE SAT and related #SAT-flavoured problems. Methodologically distant from Y4 (no Grover), but conceptually adjacent — same NP-hard combinatorial regime.
We consider an extended model of quantum computation where a scalable fault-tolerant quantum computer is coupled to one or more ancilla qubits that evolve according to a nonlinear Schrödinger equation. […] An efficient quantum circuit evaluating an n-bit Boolean function in conjunctive normal form is used to prepare an ancilla encoding its number s of satisfying assignments (0 ≤ s ≤ 2n). This is followed by a nonlinear quantum state discrimination gate on the ancilla qubit that is used to learn properties of s.
Tangential (score 1–4) — 5 papers
- 2605.14235 · score 3/10 · Quantum Advantage in Multi Agent Reinforcement Learning — VQC-based agents with shared entanglement; CHSH-based quantum-advantage claim. Tangential to Y3 only via the "claim quantum advantage in a variational setting" framing.
- 2605.14656 · score 3/10 · Blind Quantum Computation on a Modular Superconducting Processor — measurement-based protocol on a two-module flip-chip superconducting device. Same hardware family as Y6 (NISQ superconducting) but on cluster-state computation rather than foundations tests.
- 2605.14586 · score 2/10 · Fraxonium: Fractional fluxon states for qudit encoding — superconducting circuit design for leakage-protected qudits. Hardware-platform scope only.
- 2605.14640 · score 2/10 · Perfect transmission and parallel composition for quantum walks on graphs with two leads — CTQW scattering; distant cousin to Grover-on-graphs.
- 2605.14924 · score 2/10 · Nonlocal Topological Maxwell Demon Teleporting Ergotropy via Surface-Code QEC — uses surface code as a thermodynamic resource; QEC scope adjacent to NISQ but not optimisation.
Summary table
| Score | arXiv ID | Short title | Overlaps | arXiv |
|---|---|---|---|---|
| 8 | 2605.14994 | Sharp eigenvalue bounds on Kikuchi graphs + Quantum Max Cut | Y5, Y1 | link |
| 7 | 2605.13979 | Lottery tickets via a quantum-inspired classical algorithm | Y5 | link |
| 6 | 2605.14001 | QUACOD: coordinate descent for drone scheduling | Y4, Y2/Y3 | link |
| 6 | 2605.14219 | Failure-guided fuzzing for HQC programs (VQE/QAOA) | Y1, Y3 | link |
| 6 | 2605.14378 | Counterdiabatic Dicke-state preparation | Y2, Y4 | link |
| 6 | 2605.14538 | Free choices in Wigner's friend via PBR | Y6 | link |
| 5 | 2605.13980 | Reversible oracles for bounded Diophantine systems | Y4 | link |
| 5 | 2605.14395 | Interference visibility witnesses preparation contextuality | Y6 | link |
| 5 | 2605.14644 | Differentiable SDP for non-decomposable maps | Y5 | link |
| 5 | 2605.14822 | Nonlinear Hamiltonians + Boolean satisfiability | Y4 | link |
| 3 | 2605.14235 | Quantum advantage in multi-agent RL | Y3 | link |
| 3 | 2605.14656 | Blind QC on a modular superconducting processor | Y6 | link |
| 2 | 2605.14586 | Fraxonium qudit encoding | Y6 | link |
| 2 | 2605.14640 | Quantum walks on graphs with leads | Y4 | link |
| 2 | 2605.14924 | Maxwell demon teleporting ergotropy via surface code | Y6 | link |