Juan David Álvarez-Cuartas

arXiv2026

Symmetry-Protected Quantum Synchronization in Squeezed-Bath-Engineered Superradiance

A squeezed dissipative bath converts the coupling phase of a bipartite unconventional Dicke model into a control parameter that suppresses both static superradiant thresholds, opening a window where only a Hopf instability survives and the two spin ensembles synchronize completely via the shared cavity mode. The squeezed bath preserves a $\mathbb{Z}_2$ parity symmetry, so conventional broken-symmetry diagnostics vanish identically. We certify the synchronized state instead through parity-even, information-theoretic witnesses: a 30\% photon-number suppression, a Husimi-$Q$ lobe-count change, a 64\% suppression of spin--spin mutual information, and a robust discord-to-mutual-information ratio $D/I = 0.50 \pm 0.05$, confirmed by full quantum master-equation simulations. These results establish parity-even witnesses as a general, entanglement-free route to certifying quantum synchronization in symmetry-protected driven-dissipative systems.

quant-ph↗

arXiv2026

Entanglement and Dynamical Scaling Laws in Quantum Superabsorption

Quantum batteries (QBs) exploit collective quantum resources to surpass the limits of classical energy storage and power delivery. We analyze $N$-qubit cavity-coupled QBs governed by Dicke and Tavis--Cummings models under Gaussian driving and open-system dynamics. Finite-size scaling laws $\mathcal{O}(N)\!\sim\!N^α$ demonstrate an optimal region of relaxation and dephasing where coherent driving stabilizes entanglement entropy growth for thermodynamic observables (maximum energy $E_{\mathrm{max}}$, charging time $τ$, and maximum power $\bar{P}_{\mathrm{max}}$) and for qubit and cavity entanglement entropies. The Dicke model exhibits entropy-suppressed extensive behavior, while the Tavis--Cummings model achieves super-extensive scaling with $α_{E_{\mathrm{max}}}\!\in\![1.08,1.26]$, $α_τ\!\approx\!-0.49$, $α_{\bar{P}_{\mathrm{max}}}\!\in\![1.57,1.73]$, supported by qubit-cavity entanglement. We demonstrate that dissipation can act as a stabilizer source, yielding scaling benchmarks that are relevant to several experimental platforms. Our findings connect entanglement, dissipation-enhanced scaling laws and superabsorption, outlining a pathway towards scalable quantum batteries offering practical quantum advantage.

quant-ph↗