Quench of a symmetry-broken ground state

Giampaolo, Salvatore Marco; Zonzo, G.

doi:10.1103/physreva.95.012121

Cited by 3 publications

(7 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, when the set of the parameters after the quench lives in the region of the disordered phase, ρ x (t) and ρ y (t) have, in addiction to the exponential decay, an oscillatory behavior, that is absent in the other case. This picture is in agreement with the results obtained in the cases of the quantum-Ising model and the cluster-Ising models [42,[50][51][52]. For what concern the eqs.…”

supporting

confidence: 91%

“…However the evolution induced by a sudden quench of the Hamiltonian parameters of a many-body system preserves the parity. In fact if a state before the quench has a defined parity, then the parity must be preserved also during the evolution [42]. At the level of a single spin, ground states with a defined parity are characterized by the fact that ρ x (0) = ρ y (0) = 0.…”

mentioning

confidence: 99%

“…The exact results are obtained by considering, 5), by using the approach described in Ref. [42], while the lines are the result of a fit obtained using eqs. as initial state, a symmetry-breaking ground state.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Geometric phase of quenched spin models

Zonzo¹,

Capolupo²,

Giampaolo³

2017

Preprint

View full text Add to dashboard Cite

We consider a one dimensional spin-1/2 many body systems which initial state is a symmetry broken ground state and in which an evolution is induced by a sudden quench of the Hamiltonian parameters. We show that the long-time behavior of the spin state, can be approximated by the one of an open two level system in which the evolution preserves all the symmetries of the Hamiltonian. Exploiting such a result we analyze the geometric phase associated with the evolution of the single spin state and we prove analytically that its long-time behavior depends on the physical phase realized after the quench. When the system arrives in a paramagnetic phase, the geometric phase shows a periodicity that is absent in the other cases. Such a difference also survives in finite size systems until boundary effects come into play. We also discuss the effects of a explicit violation of the parity symmetry of the Hamiltonian and possible applications to the problem of the entanglement thermalization.

show abstract

supporting

confidence: 91%

mentioning

confidence: 99%

See 1 more Smart Citation

Geometric phase of quenched spin models

Zonzo¹,

Capolupo²,

Giampaolo³

2017

Preprint

View full text Add to dashboard Cite

show abstract

“…Recently, also atoms in a solid have been proven to be genuinely multipartite entangled [36,37]. Topological and nematic phase transitions in spin chains are shown to be ruled by genuine multipartite entanglement [38][39][40], even if bipartite entanglement dies out [41].…”

Section: Entanglement Properties Of the Pure 3-photon-statesmentioning

confidence: 99%

Genuine Multipartite Entanglement in the 3-Photon Decay of Positronium

Hiesmayr¹,

Moskal²

2017

Sci Rep

View full text Add to dashboard Cite

The electron-positron annihilation into two photons is a standard technology in medicine to observe e.g. metabolic processes in human bodies. A new tomograph will provide the possibility to observe not only direct e + e − annihilations but also the 3 photons from the decay of ortho-positronium atoms formed in the body. We show in this contribution that the three-photon state with respect to polarisation degrees of freedom depends on the angles between the photons and exhibits various specific entanglement features. In particular genuine multipartite entanglement, a type of entanglement involving all degrees of freedom, is subsistent if the positronium was in a definite spin eigenstate. Remarkably, when all spin eigenstates are mixed equally, entanglement –and even stronger genuine multipartite entanglement– survives. Due to a “symmetrization” process, however, Dicke-type or W-type entanglement remains whereas GHZ-type entanglement vanishes. The survival of particular entanglement properties in the mixing scenario may make it possible to extract quantum information in the form of distinct entanglement features, e.g., from metabolic processes in human bodies.

show abstract

“…The importance of this family of fully analytically solv-able models is the presence of exotic phases, such as nematic and topological phases. Hence, it can provide a new field to study hot topics of the current research, as the presence of global entanglement [44] or the effects of a sudden quench of the Hamiltonian parameters, for ground states that violate the symmetries of the system [45]. Moreover, this family of models can be generalized with respect to higher dimensions, both in space and degrees of freedom, and may become a prototype for studying the possible applications of quantum information tasks.…”

Section: Discussionmentioning

confidence: 99%

n-cluster models in a transverse magnetic field

Zonzo¹,

Giampaolo²

2018

J. Stat. Mech.

View full text Add to dashboard Cite

In this paper we analyze a family of one dimensional fully analytically solvable models, named the n-cluster models in a transverse magnetic field, in which a many-body cluster interaction competes with a uniform transverse magnetic field. These models, independently by the cluster size n + 2, exhibit a quantum phase transition, that separates a paramagnetic phase from a cluster one, that corresponds to a nematic ordered phase or a symmetry-protected topological ordered phase for even or odd n respectively. Due to the symmetries of the spin correlation functions, we prove that these models have no genuine multipartite entanglement. On the contrary, for a magnetic field strong enough, a non vanishing concurrence arises between spins at the endpoints of the cluster. Due to their integrability and entanglement properties, the n-cluster models in a transverse magnetic field may serve as a prototype for studying non trivial-spin orderings and as a potential reference system for the applications of quantum information tasks.

show abstract

Quench of a symmetry-broken ground state

Cited by 3 publications

References 55 publications

Geometric phase of quenched spin models

Geometric phase of quenched spin models

Genuine Multipartite Entanglement in the 3-Photon Decay of Positronium

n-cluster models in a transverse magnetic field

Contact Info

Product

Resources

About