Spin‐Chain‐Star Systems: Entangling Multiple Chains of Spin Qubits

Abstract

We consider spin‐chain‐star systems characterized by N‐wise many‐body interactions between the spins in each chain and the central one. We show that such systems can be exactly mapped into standard spin‐star systems through unitary transformations. Such an approach allows the solution of the dynamic problem of an XX$X X$ spin‐chain‐star model and transparently shows the emergence of quantum correlations in the system, based on the idea of entanglement between chains.

SU(2)-Symmetric Exactly Solvable Models of Two Interacting Qubits

“…Finally, it is worth pointing out that the relevance of the present work relies also on the fact that it opens the possibility to analogously investigate: 1) other possible exactly solvable scenarios for the same model; 2) other finite representations of the SU(2)-symmetry group which can be interpreted in terms of more complex systems of interacting qubits [77,78] and/or qudits (N-level systems) [69,79,80]. For example, the 6 × 6 representation matrix can be written in terms of a qubit coupled to a qutrit (threelevel system), as well as the eight-dimensional matrix can be expressed in terms of three interacting qubit operators.…”

Characterization of Quantum and Classical Critical Points for an Integrable Two-Qubit Spin–Boson Model

“…What deserves to be remarked on is also the fact that our rigorous and exact approach allows the obtaining of analytical results, and, thanks to its generality, it can be applied to other different scenarios and/or other models, opening a wide range of further investigations to better characterize such kind of systems useful for the future quantum technologies. Such an approach is based on the identification of symmetry-induced and symmetryprotected subspaces, thanks to which the dynamical problem can be broken down into relatively easier and treatable (sub)problems, as it happens in different scenarios [84][85][86].…”

Invariant-Parameterized Exact Evolution Operator for SU(2) Systems with Time-Dependent Hamiltonian

“…We mention, incidentally, that in the literature time-dependent SU(2) models have been considered which can be solved exactly without resorting to the Lewis and Riesenfeld theory [51][52][53][54][55][56][57][58][59][60][61][62][63][64][65][66][67]. It should also be emphasized that recent studies have usefully leveraged on the knowledge of the evolution operator for time-dependent single spin 1/2 models to derive the exact dynamics of quite general multi-spin time-dependent models [68][69][70][71][72][73][74][75][76][77][78][79][80][81][82][83][84][85].…”