Quantum Entanglement | 李梓民 Zi-Min Li

Quantum Chaos and Entanglement Dynamics

Wed, 15 Jul 2026 00:00:00 +0000

Quantum chaos and entanglement are related but distinct aspects of quantum dynamics. We investigate spectral statistics and out-of-time-order correlators in Rabi-type models, examining the roles of symmetry and integrability and the limits of different chaos diagnostics.

A complementary strand studies entanglement structure and state preparation in coupled qubit-oscillator systems. We explore how interactions, detuning, and parameter ramps redistribute quantum correlations and enable controlled preparation of entangled states.

Our 2026 preprint on tripartite quantum Rabi models studies static entanglement structure and adiabatic Bell-state preparation. It is listed as a preprint, separately from peer-reviewed journal publications. Current projects also explore asymmetric and mixed-coupling extensions.

Entanglement and Bell-State Preparation in the Tripartite Quantum Rabi Model

Sat, 11 Jul 2026 00:00:00 +0000

How can a simple light-matter interaction reorganize two-qubit entanglement, and can that structure be used to prepare a useful quantum state? Our recent preprint studies these questions in the tripartite quantum Rabi model, where two qubits interact collectively with a single bosonic mode.

In the zero-detuning limit, the spectrum separates into branches with sharply different entanglement properties. Some triplet states carry no two-qubit entanglement, while others are maximally entangled; the antisymmetric singlet ladder remains decoupled. Finite detuning turns selected crossings into avoided crossings, allowing entanglement to move between eigenbranches.

This spectral picture suggests a state-preparation strategy. Starting from a nearly separable state at weak coupling, one can slowly increase the collective coupling and follow an eigenbranch that becomes dominated by a Bell-state component. A compact three-state model explains the relevant mixing, while finite-time simulations identify the coupling strength and ramp duration needed for high final fidelity.

The work links a static question, the organization of entanglement in the spectrum, to a dynamical one, the preparation of a Bell state within a finite time.

Read the preprint on arXiv

Static Entanglement Structure and Adiabatic Bell-State Preparation in the Tripartite Quantum Rabi Model

Sat, 11 Jul 2026 00:00:00 +0000