BackBrowsing Artículos by Author "Tóth, Géza"
Now showing items 1-8 of 8
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Activating hidden metrological usefulness
(American Physical Society, 2020-07-07)[EN] We consider bipartite entangled states that cannot outperform separable states in any linear interferometer. Then, we show that these states can still be more useful metrologically than separable states if several ... -
Bound Entangled Singlet-Like States for Quantum Metrology
(American Physical Society, 2021-05-10)Bipartite entangled quantum states with a positive partial transpose (PPT), i.e., PPT entangled states, are usually considered very weakly entangled. Since no pure entanglement can be distilled from them, they are also ... -
Entanglement and extreme spin squeezing of unpolarized states
(IOP Publishing, 2017-01-20)We present criteria to detect the depth of entanglement in macroscopic ensembles of spin-j particles using the variance and second moments of the collective spin components. The class of states detected goes beyond traditional ... -
Entanglement loss in molecular quantum-dot qubits due to interaction with the environment
(IOP Publishing, 2018-05-16)We study quantum entanglement loss due to environmental interaction in a condensed matter system with a complex geometry relevant to recent proposals for computing with single electrons at the nanoscale. We consider a ... -
Entanglement witnesses in the XY chain: Thermal equilibrium and postquench nonequilibrium states
(American Physical Society, 2023-03)We use entanglement witnesses to detect entanglement in the XY chain in thermal equilibrium and determine the temperature bound below which the state is detected as entangled. We consider the entanglement witness based on ... -
Measurement-induced, spatially-extended entanglement in a hot, strongly-interacting atomic system
(Nature, 2020-05-15)Quantum technologies use entanglement to outperform classical technologies, and often employ strong cooling and isolation to protect entangled entities from decoherence by random interactions. Here we show that the opposite ... -
Number-phase uncertainty relations and bipartite entanglement detection in spin ensembles
(Verein Forderung Open Access Publizierens Quantenwissenschaf, 2023-02)We present a method to detect bipartite entanglement based on number-phase-like uncertainty relations in split spin ensembles. First, we derive an uncertainty relation that plays the role of a number-phase uncertainty for ... -
Permutationally invariant state reconstruction
(IOP Publishing, 2012-10)Feasible tomography schemes for large particle numbers must possess, besides an appropriate data acquisition protocol, an efficient way to reconstruct the density operator from the observed finite data set. Since state ...