We study effective spin interactions arising from quantum electrodynamics (QED) scattering between localized fermionic spins. By integrating out photon and mediator fields, the dynamics reduce to an effective spin Hamiltonian. For two qubits in the nonrelativistic regime, the resulting interaction takes a tensor dipolar form with an asymptotic decay proportional to \(R^{-3}\). We obtain analytical expressions for the entanglement negativity, highlighting its dependence on coupling strength and spatial configuration. We then examine a setup in which two bath spins interact via a sequential exchange with an intermediate fermionic mediator. At the perturbative order considered, the mediator remains unentangled and induces an effective bath--bath interaction with stronger spatial suppression than in the photon-mediated case. Extending the construction to an \(N\)-spin setting yields an effective interaction network mediated by virtual exchange processes, which can support the generation of multipartite entanglement across the system.
Entanglement is a defining feature of quantum mechanics, and its relation to quantum criticality is of considerable current interest. Here we show that measurable spin and charge fluctuations provide an entanglement witness of quantum criticality in the two-impurity Kondo model, which has experimental realizations in t...
In quantum physics it is commonplace to model the interaction of remote systems with a many-body Hamiltonian. Taking such an action-at-a-distance description {\it \`a la lettre} leads to various paradoxes related to faster-than-light communication and apparent inconsistencies in local energy accounting. It also neglect...
N. Gisin, S. Massar, Jef Pauwels et al.· 0 citations
We investigate the influence of the Hawking effect on quantum entanglement by incorporating the spin degrees of freedom of Dirac fields in the background of a Garfinkle–Horowitz–Strominger (GHS) dilaton black hole. By analyzing the redistribution of correlations between causally accessible and inaccessible regions, we...
We discuss the quench dynamics of an isolated system composed of a single spinful impurity in the transverse Rabi field and bath of non-interacting three- and two-dimensional bosons. Specifically, we consider the evolution of bosons and a spin-$\frac{1}{2}$ particle, initially prepared in a Bose-Einstein condensate sta...
We study the dynamics of the cumulants of the entanglement Hamiltonian in interacting integrable models following global quantum quenches. Building on recent results based on space-time duality, we show that these cumulants are exactly given by the cumulants of currents of suitable conserved charges evaluated in the ma...
