Zobrazeno 1 - 10
of 111
pro vyhledávání: '"Abbott, Alastair A."'
Publikováno v:
Phys. Rev. A 109, 062435 (2024)
The quantum switch, the canonical example of a process with indefinite causal order, has been claimed to provide various advantages over processes with definite causal orders for some particular tasks in the field of quantum metrology. In this work,
Externí odkaz:
http://arxiv.org/abs/2312.12172
Publikováno v:
Quantum 8, 1514 (2024)
Causal nonseparability is the property underlying quantum processes incompatible with a definite causal order. So far it has remained a central open question as to whether any process with a clear physical realisation can violate a causal inequality,
Externí odkaz:
http://arxiv.org/abs/2308.12760
Publikováno v:
Phys. Rev. Research 6, L032020 (2024)
The standard model of quantum circuits assumes operations are applied in a fixed sequential "causal" order. In recent years, the possibility of relaxing this constraint to obtain causally indefinite computations has received significant attention. Th
Externí odkaz:
http://arxiv.org/abs/2307.10285
Publikováno v:
Phys. Rev. Applied 21, 034053 (2024)
We show that weakly entangled states can improve communication over a qubit channel using only separate, interference-free, measurements of individual photons. We introduce a communication task corresponding to the cryptographic primitive known as se
Externí odkaz:
http://arxiv.org/abs/2303.07907
Publikováno v:
Quantum 8, 1376 (2024)
We investigate what quantum advantages can be obtained in multipartite non-cooperative games by studying how different types of quantum resources can lead to new Nash equilibria and improve social welfare -- a measure of the quality of an equilibrium
Externí odkaz:
http://arxiv.org/abs/2211.01687
Autor:
Fellous-Asiani, Marco, Mothe, Raphaël, Bresque, Léa, Dourdent, Hippolyte, Camati, Patrice A., Abbott, Alastair A., Auffèves, Alexia, Branciard, Cyril
Publikováno v:
Phys. Rev. Research 5, 023111 (2023)
Quantum mechanics allows processes to be superposed, leading to a genuinely quantum lack of causal structure. For example, the process known as the quantum switch applies two operations ${\cal A}$ and ${\cal B}$ in a superposition of the two possible
Externí odkaz:
http://arxiv.org/abs/2208.01952
Autor:
Ioannou, Marie, Sekatski, Pavel, Abbott, Alastair A., Rosset, Denis, Bancal, Jean-Daniel, Brunner, Nicolas
Publikováno v:
New J. Phys. 24 063006 (2022)
We discuss quantum key distribution protocols and their security analysis, considering a receiver-device-independent (RDI) model. The sender's (Alice's) device is partially characterized, in the sense that we assume bounds on the overlaps of the prep
Externí odkaz:
http://arxiv.org/abs/2111.04351
Publikováno v:
Phys. Rev. Lett. 129, 090402 (2022)
While the standard formulation of quantum theory assumes a fixed background causal structure, one can relax this assumption within the so-called process matrix framework. Remarkably, some processes, termed causally nonseparable, are incompatible with
Externí odkaz:
http://arxiv.org/abs/2107.10877
Autor:
Ioannou, Marie, Pereira, Maria Ana, Rusca, Davide, Grünenfelder, Fadri, Boaron, Alberto, Perrenoud, Matthieu, Abbott, Alastair A., Sekatski, Pavel, Bancal, Jean-Daniel, Maring, Nicolas, Zbinden, Hugo, Brunner, Nicolas
Publikováno v:
Quantum 6, 718 (2022)
We present protocols for quantum key distribution in a prepare-and-measure setup with an asymmetric level of trust. While the device of the sender (Alice) is partially characterized, the receiver's (Bob's) device is treated as a black-box. The securi
Externí odkaz:
http://arxiv.org/abs/2104.14574
Publikováno v:
PRX Quantum 2, 030335 (2021)
Quantum supermaps are transformations that map quantum operations to quantum operations. It is known that quantum supermaps which respect a definite, predefined causal order between their input operations correspond to fixed-order quantum circuits. A
Externí odkaz:
http://arxiv.org/abs/2101.08796