TY - JOUR

T1 - Bounds on the speedup in quantum signaling

AU - Arrighi, Pablo

AU - Nesme, Vincent

AU - Werner, Reinhard F.

N1 - Funding information: This work has been funded by the ANR-12-BS02-007-01 TARMAC grant, the ANR-10-JCJC-0208 CausaQ grant, and the Deutsche Forschungsgemeinschaft (Forschergruppe 635). We thank the anonymous referee whose comments both made the paper more precise and triggered further insights.

PY - 2017/1/26

Y1 - 2017/1/26

N2 - Given a classical, reversible dynamics over a line of discrete systems, we can define a quantum evolution, which acts on basis states like the classical one but is linearly extended to allow for quantum superpositions. It is a curious fact that in the quantum regime, the speed of propagation of information can sometimes be much greater than in the classical regime. Here we provide optimal bounds on this quantum speedup. In particular we show that over a run of many steps, the quantum propagation neighborhood can only increase by a constant fringe, so that there is no asymptotic increase in speed.

AB - Given a classical, reversible dynamics over a line of discrete systems, we can define a quantum evolution, which acts on basis states like the classical one but is linearly extended to allow for quantum superpositions. It is a curious fact that in the quantum regime, the speed of propagation of information can sometimes be much greater than in the classical regime. Here we provide optimal bounds on this quantum speedup. In particular we show that over a run of many steps, the quantum propagation neighborhood can only increase by a constant fringe, so that there is no asymptotic increase in speed.

UR - http://www.scopus.com/inward/record.url?scp=85011554735&partnerID=8YFLogxK

U2 - 10.1103/PhysRevA.95.012331

DO - 10.1103/PhysRevA.95.012331

M3 - Article

VL - 95

SP - 012331

JO - Phys. Rev. A

JF - Phys. Rev. A

SN - 2469-9934

IS - 1

M1 - 012331

ER -