aiqbench analysis
This study confirms that collective photon echoes in the Tavis-Cummings model are robust against initial photon distributions and survive cavity decay, making them viable for near-term observation on existing five-qubit superconducting hardware. The research identifies distinct dynamical regimes governed by detuning and demonstrates that photons effectively shield themselves from loss while residing within emitters. These findings advance our understanding of few-photon quantum dynamics and offer a practical pathway for implementing echo-based protocols in current quantum devices.
Collective photon echoes in the Tavis-Cummings model: distribution independence, two detuning regimes, and the Dicke ladder
arXiv:2608.21442v1 Announce Type: new Abstract: An ensemble of $N$ two-level molecules prepared in its ground state and sharing a lossless cavity with a weak field does not simply absorb: the intensity collapses and then recurs, in a train of collective photon echoes. Working from the exact solution of the Tavis-Cummings model in the few-photon regime $\bar n<N$, we confirm the echo time $\tau_E=4\pi\sqrt{N+\Delta}/g$ numerically at resonance from $N=5$ to $400$, the small-$N$ end discriminating this form from the alternative $4\pi\sqrt{N-\bar n+\Delta}/g$ in its favor. The initial state requires no preparation, being the ground state. The echo time is independent of the initial photon distribution: coherent, thermal, squeezed and oscillatory-squeezed distributions spanning variances from 2 to 34 all recur together, as does a controlled pair with identical mean and variance differing only in the shape of $\rho_{nn}$. The echo amplitude is not: it varies at the tens-of-percent level at fixed mean, including a factor of 1.8 with the squeezing phase at fixed squeezing strength. Detuning organizes the dynamics into two clean regimes separated by a fragmented crossover, the dispersive-branch echo time approaching one-half the resonant one, and sufficient detuning removes the dependence on the initial Dicke state. For arbitrary initial Dicke state, emission replaces absorption at $m\simeq-N/2+\bar n$, and the echo envelope acquires one component per step up the ladder: a single-component echo occurs only at the ground state. A feasibility analysis against a five-qubit superconducting device, with Lindblad simulations of cavity decay and dephasing and full-Hilbert-space disorder simulations, shows the first echoes observable at $N\sim5$-$20$ on existing hardware: the echo survives the dominant loss channel with contrast $\sim e^{-\kappa\tau_E/2}$, photons being shielded from cavity decay while resident in the emitters.
Abstract:An ensemble of $N$ two-level molecules prepared in its ground state and sharing a lossless cavity with a weak field does not simply absorb: the intensity collapses and then recurs, in a train of collective photon echoes. Working from the exact solution of the Tavis-Cummings model in the few-photon regime $\bar n<N$, we confirm the echo time $\tau_E=4\pi\sqrt{N+\Delta}/g$ numerically at resonance from $N=5$ to $400$, the small-$N$ end discriminating this form from the alternative $4\pi\sqrt{N-\bar n+\Delta}/g$ in its favor. The initial state requires no preparation, being the ground state. The echo time is independent of the initial photon distribution: coherent, thermal, squeezed and oscillatory-squeezed distributions spanning variances from 2 to 34 all recur together, as does a controlled pair with identical mean and variance differing only in the shape of $\rho_{nn}$. The echo amplitude is not: it varies at the tens-of-percent level at fixed mean, including a factor of 1.8 with the squeezing phase at fixed squeezing strength. Detuning organizes the dynamics into two clean regimes separated by a fragmented crossover, the dispersive-branch echo time approaching one-half the resonant one, and sufficient detuning removes the dependence on the initial Dicke state. For arbitrary initial Dicke state, emission replaces absorption at $m\simeq-N/2+\bar n$, and the echo envelope acquires one component per step up the ladder: a single-component echo occurs only at the ground state. A feasibility analysis against a five-qubit superconducting device, with Lindblad simulations of cavity decay and dephasing and full-Hilbert-space disorder simulations, shows the first echoes observable at $N\sim5$-$20$ on existing hardware: the echo survives the dominant loss channel with contrast $\sim e^{-\kappa\tau_E/2}$, photons being shielded from cavity decay while resident in the emitters.
Quantum Physics (quant-ph); Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
arXiv:2608.21442 [quant-ph]
(or arXiv:2608.21442v1 [quant-ph] for this version)
https://doi.org/10.48550/arXiv.2608.21442 Focus to learn more arXiv-issued DOI via DataCite
P3_supplement_checks.py
SUPPLEMENT-README.txt
general_case-Fast__with_navigation__v7.nb
arXivLabs is a framework that allows collaborators to develop and share new arXiv features directly on our website.
Both individuals and organizations that work with arXivLabs have embraced and accepted our values of openness, community, excellence, and user data privacy. arXiv is committed to these values and only works with partners that adhere to them.
Have an idea for a project that will add value for arXiv's community? Learn more about arXivLabs.
Full text under the publisher's open licence · 375 words
