aiqbench analysis
This is a theoretical quantum-physics paper, not a product or experiment. It proposes a closed, Hermitian squeezing-Dicke model that displays non-Hermitian behaviour (an effective PT symmetry and exceptional points) without dissipation, and it claims a nonreciprocal quantum amplification effect. Its relevance to quantum technology is prospective: the amplification idea is a candidate design principle, but the paper offers no hardware demonstration or near-term application.
Non-Hermiticity of an anomalous superradiant phase
arXiv:2606.26770v2 Announce Type: replace Abstract: We present a Hermitian squeezing-Dicke model as a minimal closed-system setting for non-Hermitian many-body physics. Squeezing generates an effective parity-time ($\mathcal{PT}$) symmetry and exchanges gainy and lossy eigenmodes without dissipation. We identify an anomalous dynamical superradiant phase (DSRP) that exhibits by a mean-field superradiant order in the $\mathcal{PT}$ symmetry-breaking regime, accompanied by a $\mathbb{Z}_2$-symmetry-breaking ground-state quantum phase transition. Additionally, it undergoes a $\mathcal{PT}$-breaking dynamical phase transition at an exceptional point (EP). The excitation energy vanishes near both boundaries, giving critical slowing down. The vacuum photon number is divergent at the ground-state transition but is finite and nonanalytic at the EP, distinguishing the DSRP from the conventional superradiant phase and from a standard dynamical instability. Squeezing causes the coupling phase to act as an artificial magnetic flux, which yields flux-controlled nonreciprocal quantum amplification in the DSRP. Our results offer an alternative pathway to non-Hermitian many-body physics and nonreciprocal quantum amplification in closed Hermitian systems.
Abstract:We present a Hermitian squeezing-Dicke model as a minimal closed-system setting for non-Hermitian many-body physics. Squeezing generates an effective parity-time ($\mathcal{PT}$) symmetry and exchanges gainy and lossy eigenmodes without dissipation. We identify an anomalous dynamical superradiant phase (DSRP) that exhibits by a mean-field superradiant order in the $\mathcal{PT}$ symmetry-breaking regime, accompanied by a $\mathbb{Z}_2$-symmetry-breaking ground-state quantum phase transition. Additionally, it undergoes a $\mathcal{PT}$-breaking dynamical phase transition at an exceptional point (EP). The excitation energy vanishes near both boundaries, giving critical slowing down. The vacuum photon number is divergent at the ground-state transition but is finite and nonanalytic at the EP, distinguishing the DSRP from the conventional superradiant phase and from a standard dynamical instability. Squeezing causes the coupling phase to act as an artificial magnetic flux, which yields flux-controlled nonreciprocal quantum amplification in the DSRP. Our results offer an alternative pathway to non-Hermitian many-body physics and nonreciprocal quantum amplification in closed Hermitian systems.
arXiv:2606.26770 [quant-ph]
(or arXiv:2606.26770v2 [quant-ph] for this version)
https://doi.org/10.48550/arXiv.2606.26770 Focus to learn more arXiv-issued DOI via DataCite
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Full text under the publisher's open licence · 242 words