Results 21 to 30 of about 4,469 (136)

Certified randomness in quantum physics [PDF]

, 2016
The concept of randomness plays an important role in many disciplines. On one hand, the question of whether random processes exist is fundamental for our understanding of nature.
Acín, Antonio, Masanes, Lluis
core   +2 more sources

Correlations in Entanglement-Assisted Prepare-and-Measure Scenarios

PRX Quantum, 2021
We investigate the correlations that can arise between Alice and Bob in prepare-and-measure communication scenarios where the source (Alice) and the measurement device (Bob) can share prior entanglement. The paradigmatic example of such a scenario is the
Armin Tavakoli, Jef Pauwels, Erik Woodhead, Stefano Pironio   +3 more
doaj   +1 more source

Gadget structures in proofs of the Kochen-Specker theorem [PDF]

Quantum, 2020
The Kochen-Specker theorem is a fundamental result in quantum foundations that has spawned massive interest since its inception. We show that within every Kochen-Specker graph, there exist interesting subgraphs which we term $01$-gadgets, that capture ...
Ravishankar Ramanathan, Monika Rosicka, Karol Horodecki, Stefano Pironio, Michał Horodecki, Paweł Horodecki   +5 more
doaj   +1 more source

Necessary detection efficiencies for secure quantum key distribution and bound randomness [PDF]

, 2016
In recent years, several hacking attacks have broken the security of quantum cryptography implementations by exploiting the presence of losses and the ability of the eavesdropper to tune detection efficiencies.
Acín, Antonio, Cavalcanti, Daniel, Passaro, Elsa, Pironio, Stefano, Skrzypczyk, Paul   +4 more
core   +2 more sources

More randomness from noisy sources [PDF]

, 2014
Bell experiments can be used to generate private random numbers. An ideal Bell experiment would involve measuring a state of two maximally entangled qubits, but in practice any state produced is subject to noise.
Bancal, Jean-Daniel, Scarani, Valerio
core   +3 more sources

Algorithm 950: Ncpol2sdpa---Sparse Semidefinite Programming Relaxations for Polynomial Optimization Problems of Noncommuting Variables [PDF]

, 2015
A hierarchy of semidefinite programming (SDP) relaxations approximates the global optimum of polynomial optimization problems of noncommuting variables.
Wittek, Peter
core   +1 more source

Entanglement in prepare-and-measure scenarios: many questions, a few answers

New Journal of Physics, 2022
Entanglement and quantum communication are paradigmatic resources in quantum information science leading to correlations between systems that have no classical analogue.
Jef Pauwels, Armin Tavakoli, Erik Woodhead, Stefano Pironio   +3 more
doaj   +1 more source

A histories perspective on characterizing quantum non-locality

New Journal of Physics, 2014
We introduce a framework for studying non-locality and contextuality inspired by the path integral formulation of quantum theory. We prove that the existence of a strongly positive joint quantum measure—the quantum analogue of a joint probability measure—
Fay Dowker, Joe Henson, Petros Wallden
doaj   +1 more source

Information capacity of quantum communication under natural physical assumptions [PDF]

Quantum
The quantum prepare-and-measure scenario has been studied under various physical assumptions on the emitted states. Here, we first discuss how different assumptions are conceptually and formally related.
Jef Pauwels, Stefano Pironio, Armin Tavakoli   +2 more
doaj   +1 more source

Beyond Bell's theorem: correlation scenarios

New Journal of Physics, 2012
Bell's theorem witnesses that the predictions of quantum theory cannot be reproduced by theories of local hidden variables in which observers can choose their measurements independently of the source.
Tobias Fritz
doaj   +1 more source