Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 2606.22099

Transient Information Partition in Coherent Exciton-Phonon-Photon Dynamics

Kunio Ishida
View original source ↗Read source document ↗Export metadata ↓

Abstract

We study transient information partition in a coherent exciton-phonon-photon system using subsystem-resolved quantum mutual information (QMI). By employing a model with excitonic, phononic, and photonic degrees of freedom, we analyze the dynamics in the $J$-$ν$ plane, where $J$ characterizes excitonic delocalization and $ν$ denotes the exciton-phonon coupling strength. By comparing time-averaged QMI maps with the absorbed photon number, we show that optical activity alone does not determine the character of the light-induced transient state. The exciton-centered information partition identifies a broad crossover between polariton-like and polaron-like transient responses, depending on whether excitonic information is mainly shared with the photon or phonon subsystem. In contrast, the phonon-centered partition reveals a sharper boundary-adjacent redistribution ridge near the boundary between the zero- and one-exciton ground-state sectors. This ridge is absent from both the ground-state sector map and the photon-absorption map, indicating that it is neither a static sector boundary nor an enhancement of optical absorption. A variational strength-function analysis connects the ridge to a region-II-like finite-energy polaronic excitation whose dominant spectral weight lies near the one-phonon energy, and thus the ridge represents a hidden transient correlation structure in which a limited amount of phonon-related information is preferentially shared with the photon subsystem before being predominantly allocated to exciton-phonon dressing. These results show that QMI-based information partition provides a correlation-based framework for characterizing coherent light-induced transient states in which optical and material degrees of freedom jointly participate quantum mechanically.

Explore related subjects

quant-phcond-mat.other

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Kunio Ishida. 2026-06-20. Transient Information Partition in Coherent Exciton-Phonon-Photon Dynamics. https://arxiv.org/abs/2606.22099

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Iteratively decoded magic state distillation

We present numerical simulation results for the 7-to-1 and 15-to-1 state distillation circuits, constructed using transversal CNOTs acting on multiple surface code patches. The distillation circuits are decoded iteratively using the method outlined in [arXiv:2407.20976]. We show that, with a re-configurable qubit architecture, we can perform fast magic state distillation in $\sim\mathcal{O}(1)$ code cycles. We confirm that both circuits suppress an injected input logical error rate $p$ to $\mathcal{O}(p^3)$ in the presence of additional circuit-level noise. This is done with two types of stabiliser proxies, distilling logical $|-\rangle$ and $|Y\rangle$ states, the latter is the intended state of the 7-to-1 circuit while a stabiliser-proxy for the 15-to-1 circuit. We then also provide numerical evidences for actual $|T\rangle$ state distillation using the 15-to-1 circuit with a faulty-$T$ measurement, leveraging recent near-Clifford simulation tools. Finally, we outline how ZX-calculus and Pauli webs can be used to benchmark stabiliser proxies for these distillation circuits.

quant-ph↗
arXiv2026

Enhanced measurements on quantum computers via the simultaneous probing of non-commuting Pauli operators

Measuring the state of quantum computers is a highly non-trivial task, with implications for virtually all quantum algorithms. A promising avenue is multi-copy schemes, where identical copies of a quantum state are measured jointly so that all Pauli operators within the considered observable can be simultaneously assessed. Here, we present a first implementation of such a two-copy scheme in a measurement protocol. Based on Bayesian statistics, it accurately estimates not only the average of the desired observable but also the error en route. This enables an adaptive shot-allocation algorithm that preferentially samples the most uncertain Pauli terms. In regimes with many non-commuting Pauli operators, this ``double'' scheme can outperform the state-of-the-art measurement protocol in minimizing total shots for a given precision. We also numerically confirm the finding in previous theoretical works that the two-copy scheme incurs an overhead due to the square-root relationship between the variance of measured quantities and the number of measurement shots.

quant-ph↗
arXiv2026

Thermodynamics of a phaseonium-driven optomechanical Otto engine

We study an optomechanical Otto engine whose working medium is a single-mode cavity driven by beams of coherently prepared three-level phaseonium atoms. The atoms are not thermal reservoirs in the Gibbs sense; rather, their populations and ground-state coherence set the detailed-balance ratio of the cavity collision map, so that the field relaxes to a Gibbs state at an operational apparent temperature. We combine the finite-time collision-model dynamics with radiation-pressure work extraction and compare three reservoir preparations: a thermal reference at the same apparent temperatures, an incoherent atomic beam with the same populations, and the coherent phaseonium beam. We show that the phaseonium isochore charges the cavity passively: the cavity ergotropy and energy-basis coherence remain zero up to numerical precision, while the state converges to the Gibbs fixed point selected by the apparent detailed balance. We further estimate lower bounds on the cost of preparing the atomic populations and coherence, showing that the relevant advantage of phaseonium is a resource-preparation tradeoff rather than a cost-free enhancement over a thermal bath at the same temperature. Finally, we assess the finite-time performance of a two-cavity cascade with additive mechanical work accounting. Over the investigated coherence-phase range, the cascade produces approximately $47\%$--$52\%$ more power than the single-cavity engine while requiring only $65\%$--$68\%$ of the hot and cold phaseonium atoms needed by two independent engines, resulting in a $9\%$--$15\%$ enhancement of power per injected atom over a complete cycle.

quant-ph↗