quant-ph digest — 2026-05-02
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 (65 new + 15 cross = 80 entries; announce cycle Friday, 1 May 2026)
Coverage: all 80 entries scored. 19 relevant (score ≥ 1); 61 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) — 6 papers
Explicit Quantum Search Algorithm for the Densest k-Subgraph Problem
- Authors: Yu.A. Biriukov, R.D. Morozov, I.V. Dyakonov, S.S. Straupe
- arXiv: 2604.27782
- Category: new submission — Quantum Physics (quant-ph)
- Score: 9/10 (HIGH)
- Overlaps with: Y4 (method, scope)
- Why it matters: Explicit Grover circuit for densest-k-subgraph using Dicke-state initialiser and QFT-based oracle — densest-k is cardinality-constrained binary optimisation, exactly Y4's problem class. Method (Grover with cardinality-feasibility) overlaps Y4 directly.
This paper addresses the problem of finding the densest $k$-vertex subgraph in an arbitrary graph. This problem is NP-hard and has important applications in social network analysis, fraud detection, recommendation systems, and bioinformatics. We propose two quantum approaches to solve this problem: reduction to Quadratic Unconstrained Binary Optimization (QUBO) and using Grover's quantum search algorithm. For the latter approach, we present an explicit gate-based oracle circuit utilizing Dicke states and Quantum Fourier Transform for edge counting. Numerical simulations demonstrate a quadratic speedup over classical Brute-force search.
Efficient mapping of multi-constraint satisfaction problems to Rydberg platforms
- Authors: Robert Gloeckner, Shahram Panahiyan, Frederik Koch, Dieter Jaksch, Joseph Doetsch
- arXiv: 2604.27030
- Category: new submission — Quantum Physics (quant-ph)
- Score: 8/10 (HIGH)
- Overlaps with: Y2, Y4 (method, scope)
- Why it matters: xor_1 gadget enforces exactly-one constraints via Rydberg blockade — directly mirrors Y2's quasi-binary hard mixer (no penalty terms) for combinatorial optimisation. Same constraint-preserving philosophy that Y4 also exploits for cardinality-constrained search.
We present a hardware-native gadget framework for solving constraint satisfaction problems on Rydberg quantum computing architectures. Our approach introduces a compact $xor_1$ gadget that enforces exactly-one constraints, ubiquitous in combinatorial optimization, directly through geometric embedding and blockade interactions. A key advantage of the $xor_1$ gadget is its fixed, problem-size-independent detuning requirements: enforcing constraints through blockade interactions eliminates the need for large penalty terms, thereby substantially reducing the detuning range compared to Quadratic Unconstrained Binary Optimization (QUBO) formulations and improving experimental feasibility. By tailo…
Formulating Subgroup Discovery as a Quantum Optimization Problem for Network Security
- Authors: Samuel Spell, Chi-Ren Shyu
- arXiv: 2604.27153
- Category: new submission — Quantum Physics (quant-ph); Cryptography and Security (cs.CR)
- Score: 8/10 (HIGH)
- Overlaps with: Y2, Y3, Y4 (method, scope, conclusion)
- Why it matters: QUBO + QAOA on IBM hardware (ibm_pittsburgh) for subgroup discovery, with empirical 10-30 qubit NISQ scaling boundary. Mirrors Y3's end-to-end QAOA-on-NISQ workflow and Y2's QUBO formulation.
While current network intrusion detection systems achieve satisfactory accuracy, they often lack explainability. Subgroup Discovery (SD) addresses this by building interpretable rules that characterize feature interactions associated with attack traffic. With large datasets, classical heuristic beam search methods struggle with exponentially scaling search spaces and can prune critical multi-feature interactions. This paper introduces a quantum-enhanced pipeline for SD applied to network intrusion detection using NSL-KDD, formulating SD as quantum optimization for the first time. By encoding feature selection as a Quadratic Unconstrained Binary Optimization (QUBO) and solving it via the Quan…
Q3SAT-GPT: A Generative Model for Discovering Quantum Circuits for the 3-SAT Problem
- Authors: Pratim Ugale, Ilya Tyagin, Karunya Shirali, Kien X. Nguyen, Ilya Safro
- arXiv: 2604.27324
- Category: new submission — Quantum Physics (quant-ph)
- Score: 8/10 (HIGH)
- Overlaps with: Y1, Y2 (method)
- Why it matters: Mosaic Adaptive QAOA selects subsets of mixer operators per step (Y2-style hard mixer construction), and a generative model amortises QAOA circuit synthesis. The adaptive/iterative QAOA flavour overlaps Y1's iterative warm-start.
This work introduces Q3SAT-GPT, a generative model for discovering quantum circuits for the Max-E3-SAT problem. Our method learns from high-performing QAOA-style ansätze to directly generate candidate circuits. To create high-quality supervision, we also introduce Mosaic Adaptive QAOA (MosaicADAPT-QAOA), an adaptive strategy for constructing low-depth QAOA circuits by selecting subsets of mixer operators in each step, rather than inserting operators sequentially. The resulting circuits serve as training data for the generative model, allowing it to learn effective circuit design patterns while eliminating the need for costly variational optimization at inference time. Experiments show that o…
Finite Imaginary-Time Evolution for Polynomial Unconstrained Binary Optimization
- Authors: Jaehee Kim, Juhyeon Kim, Gwonhak Lee, Kyunghyun Baek, Daniel K. Park, Jeongho Bang, Joonsuk Huh
- arXiv: 2604.27482
- Category: new submission — Quantum Physics (quant-ph)
- Score: 8/10 (HIGH)
- Overlaps with: Y1, Y2, Y3 (method, scope)
- Why it matters: Finite imaginary-time evolution (LCU + amplitude amplification) for PUBO including QUBO and MaxCut — same problem class as Y1 (MaxCut), Y2 (QUBO portfolio), Y3 (DGMVP QUBO). Alternative to QAOA.
Imaginary-time evolution is a standard primitive for ground-state preparation but is nonunitary, precluding direct quantum implementation. We develop Finite Imaginary-Time Evolution (FinITE), a finite-beta construction for diagonal Pauli-Z cost Hamiltonians arising from polynomial unconstrained binary optimization (PUBO) instances, including QUBO and HUBO cases. FinITE uses the linear-combination-of-unitaries (LCU) framework to implement a scaled imaginary-time propagator. The commuting Pauli-Z structure makes termwise block-encodings compose without product-formula error, and higher-order Pauli-Z terms are handled directly without quadratization. The structure yields an exact finite-beta id…
Towards High Performance Quantum Computing (HPQ): Parallelisation of the Hamiltonian Auto Decomposition Optimisation Framework (HADOF)
- Authors: Namasi G Sankar, Georgios Miliotis, Simon Caton
- arXiv: 2604.27836
- Category: new submission — Quantum Physics (quant-ph)
- Score: 8/10 (HIGH)
- Overlaps with: Y2, Y3, Y4 (method, scope)
- Why it matters: Hamiltonian Auto-Decomposition Optimisation Framework parallelised across IBM QPUs for large QUBO + genome-assembly instances. Same scope as Y3 (QUBO/QAOA on IBM NISQ) and Y2/Y4 (QUBO decomposition for combinatorial opt).
Practical applicability of quantum optimisation on near term devices is constrained by limited qubit counts and hardware noise, which restricts the scalability of quantum optimisation algorithms for combinatorial problems. The simulation of large quantum circuits is also difficult and constrained by memory requirement. The Hamiltonian Auto Decomposition Optimisation Framework (HADOF) addresses this by decomposing large QUBOs into smaller subproblems that can be solved iteratively on quantum or classical backends. This allows the scalability of quantum QUBO algorithms beyond device limits, as well as their simulation on classical devices. In this research, we extend the evaluation of HADOF by…
Moderately relevant (score 5–7) — 3 papers
Demonstration of Exponential Quantum Speedup with Constant-Depth Compiled Circuits for Simon's Problem
- Authors: Phattharaporn Singkanipa, Victor Kasatkin, Daniel A. Lidar
- arXiv: 2604.27457
- Category: new submission — Quantum Physics (quant-ph)
- Score: 7/10 (MED)
- Overlaps with: Y6 (scope)
- Why it matters: Demonstrates exponential speedup on IBM Boston (156-qubit Heron-class) and Miami — same superconducting NISQ platform that Y6 used for the PBR test. Different question, identical hardware regime.
We demonstrate exponential quantum speedup for a restricted-Hamming-weight version of Simon's problem on present-day superconducting quantum processors by introducing a hardware-aware compilation strategy that compiles the quantum part of each Simon query circuit to constant depth. The resulting compiled circuits have $O(1)$ depth and linear connectivity, map directly onto common device layouts, and avoid additional routing and SWAP overhead. Implemented on IBM's $156$-qubit Boston and $120$-qubit Miami processors, the resulting circuits achieve sufficiently high fidelity to exhibit algorithmic quantum speedup without error suppression. Using the number-of-queries-to-solution metric, we obse…
Permutation Invariant Optimization Problems in Quantum Information Theory: A Framework for Channel Fidelity and Beyond
- Authors: Bjarne Bergh, Marco Parentin
- arXiv: 2604.27040
- Category: new submission — Quantum Physics (quant-ph)
- Score: 6/10 (MED)
- Overlaps with: Y5 (method)
- Why it matters: SDP optimisation framework using permutation invariance / Schur-Weyl reduction. Y5 also exploits structure (Pauli sparsity) to scale SDP relaxations; both are structured-SDP techniques though to different ends.
Exploiting permutation invariance to reduce the exponential scaling of semidefinite programs in quantum information has emerged as a powerful computational technique. In this work, we develop a systematic framework for using this reduction via Schur-Weyl duality for optimization problems, and establish methods that allow one to work fully inside the permutation invariant subspace while performing operations such as (partially) applying channels and taking (partial) traces, or computing expressions like the quantum relative entropy. We then apply our techniques to the problem of computing efficient lower bounds on the channel fidelity over $n$ parallel uses of a quantum channel. The algorithm…
Congestion-free routing on quantum chips
- Authors: Mithilesh Kumar, Yusuf Tahir, Varun Daiya, Sanjana Mattaparthi, Aarav Shaurya
- arXiv: 2604.27015
- Category: new submission — Quantum Physics (quant-ph)
- Score: 5/10 (MED)
- Overlaps with: Y3 (scope)
- Why it matters: Compiler-level QAOA benchmarks under qudit routing — adjacent to Y3's NISQ-circuit-execution analysis but compilation-focused.
Limited connectivity makes nonlocal quantum gates expensive on near-neighbor hardware, where compilation typically relies on SWAP transport, inheriting both depth overhead and path congestion. We present a swap-free routing framework in which higher levels of a qudit act as orthogonal spectral buses that transport control information without moving the computational state. We show that exact congestion relief in nearest-neighbor architectures requires local Hilbert-space expansion. In this model, a nonlocal operation over a path of length $L$ requires $2L+1$ logical routing primitives, compared to the $3L$ baseline. Overlapping routes remain distinguishable through bus labels encoded in the …
Tangential (score 1–4) — 10 papers
- 2604.27042 · score 2/10 · Onset of superactivation of quantum capacity — Numerical certification of finite-blocklength superactivation via SDP-style optimisation (companion to 2604.27040).
- 2604.27125 · score 2/10 · Derivation of the Born Rule and Operational Quantum Formalism in the Accessibility Framework through Boundary Reduction — Foundations: derives Born rule operationally — adjacent to Y6's ontic/epistemic theme.
- 2604.27339 · score 2/10 · Fixed-PVM Born Rule Uniqueness from Fisher Non-Expansion and Operational Calibration — Foundations: Born rule uniqueness from Fisher non-expansion — adjacent to Y6's PBR/foundations theme.
- 2604.27648 · score 2/10 · Effective Noise Mitigation via Quantum Circuit Learning in Quantum Simulation of Integrable Spin Chains — Variational noise mitigation for NISQ simulation — tangential to Y3's NISQ noise-regime analysis.
- 2604.27886 · score 2/10 · Unentangled stoquastic Merlin-Arthur proof systems: the power of unentanglement without destructive interference — StoqMA(2) complexity classes — tangential to Y5's quantum-vs-classical (dequantisation) framing.
- 2604.27171 · score 1/10 · Structure-Aware Transformers for Learning Near-Optimal Trotter Orderings with System-Size Generalization in 1D Heisenberg Hamiltonians — ML-driven optimisation of quantum circuit choices — tangential to layerwise/parameter optimisation in Y3.
- 2604.27838 · score 1/10 · Heisenberg-limited Hamiltonian learning without short-time control — Hamiltonian learning protocol — tangential quantum-algorithm methodology.
- 2604.28009 · score 1/10 · Learning quantum disentanglement scheduling from reduced states via modular hybrid policies — Hybrid quantum-classical RL policy from reduced states — tangential VQA-style framework.
- 2604.28121 · score 1/10 · Quantum Lattice Boltzmann Solutions for Transport under 3D Spatially Varying Advection on Trapped Ion Hardware — Quantum simulation on real trapped-ion hardware — tangential NISQ workflow.
- 2604.28160 · score 1/10 · Reorganizing Quantum Measurement Records Improves Time-Series Prediction — Quantum reservoir computing on real hardware with shot-noise post-processing — tangential NISQ data-processing pattern.
Summary table
| Score | arXiv ID | Short title | Overlaps | arXiv |
|---|---|---|---|---|
| 9 | 2604.27782 | Explicit Quantum Search Algorithm for the Densest k-Subgraph Problem | Y4 | link |
| 8 | 2604.27030 | Efficient mapping of multi-constraint satisfaction problems to Rydberg platforms | Y2, Y4 | link |
| 8 | 2604.27153 | Formulating Subgroup Discovery as a Quantum Optimization Problem for Network Sec… | Y2, Y3, Y4 | link |
| 8 | 2604.27324 | Q3SAT-GPT: A Generative Model for Discovering Quantum Circuits for the 3-SAT Pro… | Y1, Y2 | link |
| 8 | 2604.27482 | Finite Imaginary-Time Evolution for Polynomial Unconstrained Binary Optimization | Y1, Y2, Y3 | link |
| 8 | 2604.27836 | Towards High Performance Quantum Computing (HPQ): Parallelisation of the Hamilto… | Y2, Y3, Y4 | link |
| 7 | 2604.27457 | Demonstration of Exponential Quantum Speedup with Constant-Depth Compiled Circui… | Y6 | link |
| 6 | 2604.27040 | Permutation Invariant Optimization Problems in Quantum Information Theory: A Fra… | Y5 | link |
| 5 | 2604.27015 | Congestion-free routing on quantum chips | Y3 | link |
| 2 | 2604.27042 | Onset of superactivation of quantum capacity | Y5 | link |
| 2 | 2604.27125 | Derivation of the Born Rule and Operational Quantum Formalism in the Accessibili… | Y6 | link |
| 2 | 2604.27339 | Fixed-PVM Born Rule Uniqueness from Fisher Non-Expansion and Operational Calibra… | Y6 | link |
| 2 | 2604.27648 | Effective Noise Mitigation via Quantum Circuit Learning in Quantum Simulation of… | Y3 | link |
| 2 | 2604.27886 | Unentangled stoquastic Merlin-Arthur proof systems: the power of unentanglement … | Y5 | link |
| 1 | 2604.27171 | Structure-Aware Transformers for Learning Near-Optimal Trotter Orderings with Sy… | Y3 | link |
| 1 | 2604.27838 | Heisenberg-limited Hamiltonian learning without short-time control | Y6 | link |
| 1 | 2604.28009 | Learning quantum disentanglement scheduling from reduced states via modular hybr… | Y3 | link |
| 1 | 2604.28121 | Quantum Lattice Boltzmann Solutions for Transport under 3D Spatially Varying Adv… | Y3, Y6 | link |
| 1 | 2604.28160 | Reorganizing Quantum Measurement Records Improves Time-Series Prediction | Y3 | link |