The quantum limit for information transmission

Akib Karim, Zixin Huang, Robert J. Chapman +3 more

Lei Wang, Jie‐Hui Huang, Jonathan P. Dowling +1 more

E. Desurvire

Presented is a quantum model describing noise generation and system accumulation from both optical amplification and nonlinearity, leading to the definition of information-capacity limits in long-haul WDM transmission.

Sebastian Horvat, Borivoje Dakić

Abstract The speed of the transmission of a physical signal from a sender to a receiver is limited by the speed of light, regardless of the physical system being classical or quantum. In this sense, quantum mechanics can not provide any enhancement of the speed of information transmission. If instead we consider that the information needing to be transmitted is not localized at the sender’s location, but dispersed throughout space, spatial coherence might provide some enhancement. In this work, we demonstrate a quantum mechanical advantage in the speed of acquirement and transmission of information globally encoded in space. We present a task for which we prove a quadratic enhancement to the information acquisition speed using quantum information carriers with respect to their classical counterpart. Our findings can naturally be applied in situations where the information source has limited power, i.e. bounded number of signals that can be sent per unit time.

Marcelo Schiffer

Cristian Antonelli, Antonio Mecozzi, Mark Shtaif +1 more

The search for schemes that minimize the energy associated with the transmission of information is a longstanding fundamental issue in communication theory. In this paper we extend fundamental limits to the energy consumption per unit of information, as given by Shannon's theory, to the quantum domain. Unlike previous studies, we address a scenario where the signal may be manipulated in an arbitrary way while propagating from the transmitter to the receiver. This situation characterizes many realistic scenarios, such as multi-span fiber-optic communication systems. We obtain the ultimate quantum limit on the energy consumption in this scenario and propose a simple binary energy modulation scheme that approaches this limit within one order of magnitude for practically relevant values of spectral efficiency. Under the same conditions, the quantum energy consumption limit of the standard optically amplified coherent communication scheme is three orders of magnitude above the ultimate identified limit. Throughout the paper we consider transmission of classical information over a quantum channel.