Filtreler

2016 - 20202
Filtreleri Sıfırla

Ayarlar

Scopus Q: Q2 × Konu: Fisher information ×

Arama Sonuçları

Listeleniyor 1 - 2 / 2
  • Küçük Resim
    Yayın
    Generating multi-photon W-like states for perfect quantum teleportation and superdense coding
    (Springer New York LLC, 2016-05-06) Li, Ke; Kong, Fanzhen; Özaydın, Fatih; Yang, Qing; Cao, Zhuo-Liang; Yang, Ming
    An interesting aspect of multipartite entanglement is that for perfect teleportation and superdense coding, not the maximally entangled W states but a special class of non-maximally entangled W-like states are required. Therefore, efficient preparation of such W-like states is of great importance in quantum communications, which has not been studied as much as the preparation of W states. In this paper, we propose a simple optical scheme for efficient preparation of large-scale polarization-based entangled W-like states by fusing two W-like states or expanding a W-like state with an ancilla photon. Our scheme can also generate large-scale W states by fusing or expanding W or even W-like states. The cost analysis shows that in generating large-scale W states, the fusion mechanism achieves a higher efficiency with non-maximally entangled W-like states than maximally entangled W states. Our scheme can also start fusion or expansion with Bell states, and it is composed of a polarization-dependent beam splitter, two polarizing beam splitters and photon detectors. Requiring no ancilla photon or controlled gate to operate, our scheme can be realized with the current photonics technology and we believe it enable advances in quantum teleportation and superdense coding in multipartite settings
  • Küçük Resim
    Yayın
    Parameter estimation with Dzyaloshinskii–Moriya interaction under external magnetic fields
    (Springer, 2020-02-01) Özaydın, Fatih; Altıntaş, Azmi Ali
    We study the effects of external magnetic fields on the precision of parameter estimation with thermal entanglement of two spins in XX model, in the presence of Dzyaloshinskii–Moriya (DM) interaction. Although DM interaction excites but external magnetic fields usually decrease quantum mechanical properties of spin systems such as entanglement, we show by calculating the quantum Fisher information that not only DM interaction D but also homogeneous magnetic field B can increase the precision of parameter estimation, overwhelming the destructive effects of thermalization. We also show that inhomogeneous magnetic field b increases (decreases) the precision of parameter estimation if it is less (greater) than D. © 2020, Springer Science+Business Media, LLC, part of Springer Nature.