Quantum memory for entangled continuous-variable states

TY - JOUR

T1 - Quantum memory for entangled continuous-variable states

AU - Jensen..[et al.], Kasper

AU - Wasilewski, Wojciech

AU - Krauter, Hanna

AU - Fernholz, Thomas

AU - Nielsen, Bo Melholt

AU - Wolf, Michael Marc

AU - Polzik, Eugene Simon

PY - 2011/1

Y1 - 2011/1

N2 - A quantum memory for light is a key element for the realization of future quantum information networks. Requirements for a good quantum memory are versatility (allowing a wide range of inputs) and preservation of quantum information in a way unattainable with any classical memory device. Here we demonstrate such a quantum memory for continuous-variable entangled states, which play a fundamental role in quantum information processing. We store an extensive alphabet of two-mode 6.0 dB squeezed states obtained by varying the orientation of squeezing and the displacement of the states. The two components of the entangled state are stored in two room-temperature cells separated by 0.5 m, one for each mode, with a memory time of 1 ms. The true quantum character of the memory is rigorously proved by showing that the experimental memory fidelity 0.52±0.02 significantly exceeds the benchmark of 0.45 for the best possible classical memory for a range of displacements.

AB - A quantum memory for light is a key element for the realization of future quantum information networks. Requirements for a good quantum memory are versatility (allowing a wide range of inputs) and preservation of quantum information in a way unattainable with any classical memory device. Here we demonstrate such a quantum memory for continuous-variable entangled states, which play a fundamental role in quantum information processing. We store an extensive alphabet of two-mode 6.0 dB squeezed states obtained by varying the orientation of squeezing and the displacement of the states. The two components of the entangled state are stored in two room-temperature cells separated by 0.5 m, one for each mode, with a memory time of 1 ms. The true quantum character of the memory is rigorously proved by showing that the experimental memory fidelity 0.52±0.02 significantly exceeds the benchmark of 0.45 for the best possible classical memory for a range of displacements.

U2 - 10.1038/nphys1819

DO - 10.1038/nphys1819

M3 - Journal article

SN - 1745-2473

VL - 7

SP - 13

EP - 16

JO - Nature Physics

JF - Nature Physics

IS - 1

ER -