Preparation of two-particle total-hyperfine-spin-singlet states via spin-changing dynamics

Abstract

We present our proposals for generating total hyperfine spin zero state for two f = 1 or two f = 2 particles, starting from initial unentangled states. We show that our goal can be achieved by exploiting spin changing dynamics and quadratic Zeeman shifts with realistic choices of external magnetic fields and evolution time intervals.

Symmetry restoring and ancilla-driven entanglement for ultra-cold spin-1 atoms in a three-site ring

“…Analogously as in [22,34] we assume that two particles are confined in double-well potentials and each of them are in the state | S, S z =| 1, 0 . Both atoms remain in the ground states of external potential throughout the whole process evolution.…”

“…Based on all those facts, Huang et al [22] have presented a very interesting example of generation of bipartite total hyperfine-zero-singlet states using hyperfine-spin-1 particles confined in an optical lattice. In that paper, authors dealt with the ground state of bosons confined in an one-dimensional lattice with one atom per site, when the system was remaining in the Mott-insulator phase.…”

“…In consequence, the ground state of the system is expected to be in the dimerized phase, and it can be considered as a collection of isolated singlet pairs. For such a system, a scheme allowing for the generation of the qutrit singlet state, starting from completely unentangled states, was presented in [22]. Such scheme can be summarized in the following way.…”

“…Such scheme can be summarized in the following way. It is known that for certain conditions (see [22]) singlet state becomes a ground state of the system. For such situation, the initial product state which is characterized by the zero value of the total S z , automatically becomes the singlet state (this process requires adiabatic changes of the external magnetic field).…”

“…In this paper, we would like to extend the bipartite model analyzed in [22] to that involving three sites. Considering the three-site QBH model describing three particles trapped in an optical lattice, which can be treated as dedicated quantum simulator of a spin system, we will concentrate on the wave function evolution leading to the generation of tripartite entangled states with specifically designed quantum properties.…”