Uniformity Bias in Ground-State Sampling Induced by Replica Alignment in Quantum Monte Carlo for Quantum Annealing
- URL: http://arxiv.org/abs/2510.10566v1
- Date: Sun, 12 Oct 2025 12:23:12 GMT
- Title: Uniformity Bias in Ground-State Sampling Induced by Replica Alignment in Quantum Monte Carlo for Quantum Annealing
- Abstract summary: Quantum Monte Carlo (QMC) is widely used to simulate quantum systems.<n>We show that QMC produces uniform ground-state probabilities, unlike QA's biased distribution.<n>This bias originates from replica alignment, caused by the energetic suppression and entropic reduction of kink configurations.
- Score: 0.688204255655161
- License: http://creativecommons.org/licenses/by/4.0/
- Abstract: Quantum annealing (QA) with a transverse field often fails to sample degenerate ground states fairly, limiting applicability to problems requiring diverse optimal solutions. Although Quantum Monte Carlo (QMC) is widely used to simulate QA, its ability to reproduce such unfair ground-state sampling remains unclear because stochastic and coherent quantum dynamics differ fundamentally. We quantitatively evaluate how accurately QMC reproduces the sampling bias in QA by comparing the final ground-state distributions from the QMC master equation and the Schr\"odinger equation. We find QMC tends to produce uniform ground-state probabilities, unlike QA's biased distribution, and that this uniformity bias strengthens as annealing proceeds. Our analysis reveals that this bias originates from replica alignment -- the dominance of configurations in which all Trotter replicas coincide -- caused by the energetic suppression and entropic reduction of kink configurations (replica mismatches). These findings clarify a fundamental limitation of discrete-time QMC in faithfully simulating QA dynamics, highlighting the importance of replica correlations and transition rules in achieving realistic ground-state sampling.
Related papers
- Symmetry Constrained Quantum Error Mitigation for the Schwinger Model [39.146761527401424]
We exploit the parity and fermion-number symmetries of a gauge theory under depolarising noise.<n>We investigate symmetry verification under digital quantum simulation.
arXiv Detail & Related papers (2026-08-21T13:49:11Z) - QnRL: Quantum-Native Reinforcement Learning [82.36163324220894]
Quantum reinforcement learning (QRL) is a promising approach to learn effective decision strategies across several applications with environments.<n>Existing QRL architectures indirectly approximate environment behavior by estimating expected outcomes, which limits their expressive power and adaptive potential.<n>Overcoming such challenges requires a novel QRL approach that exploits the distributional nature of quantum computers to directly model environment random variables as quantum state distributions.
arXiv Detail & Related papers (2026-06-06T17:54:58Z) - Born-rule statistical dynamical quantum phase transitions under measurement [3.504408436046102]
Dynamical quantum phase transitions (DQPTs) occur at times when a quantum state exhibits a nonanalytic change in its return probability.<n>We show the recovering of DQPT under high-moment average and a delocalized level distribution following critical times.
arXiv Detail & Related papers (2026-05-15T15:04:58Z) - A unified quantum computing quantum Monte Carlo framework through structured state preparation [0.0]
We extend Quantum Computing Quantum Monte Carlo (QCQMC) beyond ground-state energy estimation.<n>We show that QCQMC can address excited-state spectra via Variational Fast Forwarding and the Variational Unitary Matrix Product Operator (VUMPO)<n> Benchmarks on molecular, condensed-matter, nuclear-structure, and graph-optimization problems demostrate that the QMC diffusion step consistently improves the energy accuracy of the underlying state-preparation method.
arXiv Detail & Related papers (2026-03-26T15:59:54Z) - Active Sampling Sample-based Quantum Diagonalization from Finite-Shot Measurements [0.0]
Near-term quantum devices provide only finite-shot measurements and prepare imperfect, contaminated states.<n>This motivates algorithms that convert samples into reliable low-energy estimates without full tomography or exhaustive measurements.<n>We propose Active Sampling Sample-based Quantum Diagonalization (AS-SQD), framing SQD as an active learning problem.
arXiv Detail & Related papers (2026-03-13T19:17:33Z) - Topological Defects from Quantum Reset Dynamics [0.0]
We study the effect of randomized quantum resetting (QR) under a finite-time quench across a quantum phase transition.<n>Results suggest that a system driven across a quantum critical point exhibits the same scaling behavior under a linear quench with QR as with uncorrelated noise.
arXiv Detail & Related papers (2026-01-30T19:00:02Z) - Universal classical and quantum fluctuations in the large deviations of current of noisy quantum systems: The case of QSSEP and QSSIP [2.035631599424874]
We study the fluctuation statistics of integrated currents in noisy quantum diffusive systems.<n>We show that the cumulant generating function of the integrated current, at large scales, obeys a large deviation principle.<n>We identify the leading finite-size corrections to the current statistics.
arXiv Detail & Related papers (2026-01-23T16:45:31Z) - Fair sampling with temperature-targeted QAOA based on quantum-classical correspondence theory [0.7519872646378835]
We propose SBO-QAOA, which employs a temperature-dependent Hamiltonian encoding a Gibbs distribution as its ground state.<n> Numerical simulations show that, unlike standard QAOA, SBO-QAOA yields ground-state probabilities converging to finite-temperature values with uniform distribution among degenerate states.
arXiv Detail & Related papers (2026-01-22T17:36:32Z) - Shortcuts to adiabaticity, unexciting backgrounds, and reflectionless potentials [45.88028371034407]
We exploit the analogy with one-dimensional quantum mechanics, and the well known correspondence between Bogoliubov coefficients in the QHO and transmission/reflection amplitudes in scattering theory.<n>We show how STA completions can be understood in terms of the anti-squeezing operator.
arXiv Detail & Related papers (2026-01-16T13:02:37Z) - Maximum Independent Set via Probabilistic and Quantum Cellular Automata [0.0]
We first introduce a synchronous PCA whose dynamics drives the system toward the manifold of maximal independent sets.<n>Motivated by this behavior, we construct a QCA combining a pure dissipative phase with a constraint-preserving unitary evolution.
arXiv Detail & Related papers (2025-12-07T10:33:52Z) - From VQE To SQD: Modern Quantum Algorithms For The Electronic Structure Problem [0.0]
This thesis investigates sampling-based quantum algorithms for electronic ground state energy estimation.<n>It focuses on Quantum-Selected Configuration Interaction (QSCI) and Sample-Based Quantum Diagonalization (SQD) as near-term alternatives to the Variational Quantum Eigensolver (VQE)<n>The analysis is validated through simulations, hardware-calibrated noisy studies, and execution on IBM's 127-qubit IBM Brisbane processor.
arXiv Detail & Related papers (2025-09-25T20:39:14Z) - Cyclic Variational Quantum Eigensolver: Escaping Barren Plateaus through Staircase Descent [4.517663944296433]
We introduce the Cyclic Variational Quantum Eigensolver (CVQE), a hardware-efficient framework for accurate ground-state quantum simulation.<n>CVQE departs from conventional VQE by incorporating a measurement-driven feedback cycle.<n>We show that CVQE consistently maintains chemical precision across correlation regimes, outperforms fixed UCCSD by several orders of magnitude, and achieves favorable accuracy-cost trade-offs.
arXiv Detail & Related papers (2025-09-16T13:54:03Z) - Quantum Sequential Universal Hypothesis Testing [62.751483592497806]
Quantum hypothesis testing (QHT) concerns the statistical inference of unknown quantum states.<n>We introduce the quantum sequential universal test (QSUT), a novel framework for sequential QHT in the general case of composite hypotheses.<n> QSUT builds on universal inference, and it alternates between adaptive local measurements aimed at exploring the hypothesis space and joint measurements optimized for maximal discrimination.
arXiv Detail & Related papers (2025-08-29T12:50:04Z) - Ground or Excited State: a State-Specific Variational Quantum
Eigensolver for Them All [0.0]
Variational Quantum Eigensolver (VQE) provides a lucrative platform to determine molecular energetics in quantum devices.
We propose a unified VQE framework that treats the ground and excited states in the same footings.
We introduce the notion of totally symmetric, spin-scalar unitary which maintains the purity of the reference at each step of the optimization.
arXiv Detail & Related papers (2023-08-21T13:39:58Z) - Importance sampling for stochastic quantum simulations [68.8204255655161]
We introduce the qDrift protocol, which builds random product formulas by sampling from the Hamiltonian according to the coefficients.
We show that the simulation cost can be reduced while achieving the same accuracy, by considering the individual simulation cost during the sampling stage.
Results are confirmed by numerical simulations performed on a lattice nuclear effective field theory.
arXiv Detail & Related papers (2022-12-12T15:06:32Z) - Fermionic approach to variational quantum simulation of Kitaev spin
models [50.92854230325576]
Kitaev spin models are well known for being exactly solvable in a certain parameter regime via a mapping to free fermions.
We use classical simulations to explore a novel variational ansatz that takes advantage of this fermionic representation.
We also comment on the implications of our results for simulating non-Abelian anyons on quantum computers.
arXiv Detail & Related papers (2022-04-11T18:00:01Z) - Amplifying quantum correlations with quench dynamics in a quantum spin
chain: Steady-states versus ground-states [0.0]
We analyze the behavior of steady-state quantum correlations (QCs) in the spin-1/2 transverse field XY chains analytically.
We show that steady-state QCs are strikingly greater than the equilibrium ones in its ground-state.
Our work may be testable with the current class of trapped-ion or ultracold-atom experiments.
arXiv Detail & Related papers (2022-02-13T15:05:27Z) - Error mitigation and quantum-assisted simulation in the error corrected
regime [77.34726150561087]
A standard approach to quantum computing is based on the idea of promoting a classically simulable and fault-tolerant set of operations.
We show how the addition of noisy magic resources allows one to boost classical quasiprobability simulations of a quantum circuit.
arXiv Detail & Related papers (2021-03-12T20:58:41Z) - Sampling Overhead Analysis of Quantum Error Mitigation: Uncoded vs.
Coded Systems [69.33243249411113]
We show that Pauli errors incur the lowest sampling overhead among a large class of realistic quantum channels.
We conceive a scheme amalgamating QEM with quantum channel coding, and analyse its sampling overhead reduction compared to pure QEM.
arXiv Detail & Related papers (2020-12-15T15:51:27Z) - Probing eigenstate thermalization in quantum simulators via
fluctuation-dissipation relations [77.34726150561087]
The eigenstate thermalization hypothesis (ETH) offers a universal mechanism for the approach to equilibrium of closed quantum many-body systems.
Here, we propose a theory-independent route to probe the full ETH in quantum simulators by observing the emergence of fluctuation-dissipation relations.
Our work presents a theory-independent way to characterize thermalization in quantum simulators and paves the way to quantum simulate condensed matter pump-probe experiments.
arXiv Detail & Related papers (2020-07-20T18:00:02Z)
This list is automatically generated from the titles and abstracts of the papers in this site.
This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.