Controlled generation of genuine multipartite entanglement in Floquet Ising spin models

Abstract

We propose a method for generation of genuine multipartite entangled states in a short-range Ising spin chain with periodic global pulses of magnetic field. We consider an integrable and a non-integrable Floquet system that are periodic in time and have constant quasi-energy gaps with degeneracies. We start with all spins polarized along one direction and show that they evolve into states with high entanglement by calculating the average entanglement entropy and geometric measure of entanglement. We show that some of these states have a high number of parties involved in the entanglement by calculating the quantum Fisher information. Such controlled generation of multipartite entanglement has potential applications in quantum information processing.

Floquet integrability and long-range entanglement generation in the one-dimensional quantum Potts model

“…( 15) is already simple enough to work with and it has been investigated for various models and settings, see, e.g., Refs. [19,20,[22][23][24][25][26][27][28][30][31][32][33]…”

“…In this system, the consecutive switching of the interaction between the spins on even and odd links of the chain transforms the initial short-range entanglement between the the nearest-neighbor spins into the nonlocal one. A similar protocol was later studied for the case of the 1D TFIM, where the nonlocal entanglement between the pairs of distant spins is generated by repeatedly switching the transverse field on and off [30][31][32][33]. A natural question is whether these long-range entanglement protocols can be extended beyond the spin-1/2 chains, such as the Heisenberg or Ising model, to the case of Z n chains, e.g., n-state Potts model.…”

Growth of genuine multipartite entanglement in random unitary circuits

“…However, the growth rate is relatively slow in the case of a random Clifford circuit, and in this case, to reach the same saturation value, a large number of circuit iterations is required. Recently, there have been both theoretical proposals [80,81] and experimental developments [43][44][45][46] on controlled preparation of highly multipartite entangled states. In that respect, our results propose a scheme for generation of a highly multipartite entangled state from a relatively simpler and less structured model, which could be a promising scheme for efficient generation and control of multipartite entangled states.…”

Floquet integrability and long-range entanglement generation in the one-dimensional quantum Potts model

“…( 15) is already simple enough to work with and it has been investigated for various models and settings, see e.g. [20][21][22][23][24][25][26][27][28][30][31][32][33]…”

“…In this system, the consecutive switching of the interaction between the spins on even and odd links of the chain transforms the initial short-range entanglement between the the nearest-neighbour spins into the non-local one. A similar protocol was later studied for the case of the 1D TFIM, where the non-local entanglement between the pairs of distant spins is generated by repeatedly switching the transverse field on and off [30][31][32][33]. A natural question is whether these long-range entanglement protocols can be extended beyond the spin-1/2 chains, such as the Heisenberg or Ising model, to the case of Z n chains, e.g.…”