TY - JOUR
T1 - Fundamental Limit on the Power of Entanglement Assistance in Quantum Communication
AU - Wolff, Lasse H.
AU - Belzig, Paula
AU - Christandl, Matthias
AU - Durhuus, Bergfinnur
AU - Tomamichel, Marco
PY - 2025
Y1 - 2025
N2 - The optimal rate of reliable communication over a quantum channel can be enhanced by preshared entanglement. Whereas the enhancement may be unbounded in infinite-dimensional settings even when the input power is constrained, a long-standing conjecture asserts that the ratio between the entanglement-assisted and unassisted classical capacities is bounded in finite-dimensional settings [Bennett et al., IEEE Trans. Inf. Theory 48, 2637 (2002)IETTAW0018-944810.1109/TIT.2002.802612]. In this Letter, we prove this conjecture by showing that their ratio is upper bounded by o(d2), where d is the input dimension of the channel. An application to quantum communication with noisy encoders and decoders is given. © 2025 authors. Published by the American Physical Society.
AB - The optimal rate of reliable communication over a quantum channel can be enhanced by preshared entanglement. Whereas the enhancement may be unbounded in infinite-dimensional settings even when the input power is constrained, a long-standing conjecture asserts that the ratio between the entanglement-assisted and unassisted classical capacities is bounded in finite-dimensional settings [Bennett et al., IEEE Trans. Inf. Theory 48, 2637 (2002)IETTAW0018-944810.1109/TIT.2002.802612]. In this Letter, we prove this conjecture by showing that their ratio is upper bounded by o(d2), where d is the input dimension of the channel. An application to quantum communication with noisy encoders and decoders is given. © 2025 authors. Published by the American Physical Society.
U2 - 10.1103/PhysRevLett.134.020802
DO - 10.1103/PhysRevLett.134.020802
M3 - Journal article
VL - 134
JO - Physical Review Letters
JF - Physical Review Letters
SN - 0031-9007
IS - 2
M1 - 020802
ER -