Quantum Simultaneous Information and Power Transfer: Capacity-Power Trade-offs in Discrete and Continuous Channels

2026-05-29

AI Summary

This study addresses the joint transmission of classical information and energy in quantum communication by proposing the first unified framework for Quantum Simultaneous Information and Power Transfer (QSIPT). Built upon shared quantum states, the framework enables coordinated communication and energy harvesting over both discrete- and continuous-variable channels, introducing a capacity–power function to characterize their fundamental trade-off. For discrete-variable channels, closed-form expressions are derived for the quantum erasure channel, along with tight upper and lower bounds for the amplitude damping channel. In the continuous-variable regime, a tunable transmissivity beam-splitter receiver and a joint optimization mechanism are designed; it is shown that coherent states outperform squeezed states in phase-insensitive channels, while thermal states are suitable only for energy transfer. Closed-form capacity–power expressions are further provided for various Gaussian encodings.

Abstract

This paper introduces a new framework for quantum simultaneous information and power transfer (QSIPT), enabling the joint use of quantum states for classical information and energy transfer in quantum communication systems. We propose a novel model in which quantum states are simultaneously used to transmit classical information through a quantum channel and transfer energy to an energy harvesting (EH) receiver. The trade-off between communication rate and harvested energy is characterized by the capacity-power function, which is defined and characterized for both discrete-variable (DV) and continuous-variable (CV) quantum channels. For DV channels, we derive the properties of the capacity-power function, providing analytical upper and lower bounds for the amplitude damping channel and an exact closed-form characterization for the quantum erasure channel. For CV channels, we extend the mathematical framework by introducing a generalized beam-splitter (BS) receiver with adjustable transmissivity, jointly optimized with a transmitter mean-photon-number budget, that splits the channel output between the information decoder and the EH receiver. Specifically, we analyze the capacity-power trade-off under various Gaussian encoding schemes including coherent, squeezed, and thermal states for both lossy bosonic and additive Gaussian noise channels. Closed-form expressions are derived for coherent-state encoding under the joint photon-number-budget and adjustable-transmissivity formulation; squeezed-state inputs are evaluated numerically. Our results show that, within the considered displaced Gaussian encoding class, coherent states achieve the best capacity-power trade-off, squeezed states do not outperform coherent-state encoding under the phase-insensitive channel and passive receiver architecture, and thermal states enable energy transfer without supporting reliable communication.

Problem

• quantum communication
• simultaneous information and power transfer
• capacity-power trade-off
• energy harvesting
• quantum channels

Innovation

• quantum simultaneous information and power transfer
• capacity-power trade-off
• discrete-variable quantum channel
• continuous-variable quantum channel
• generalized beam-splitter receiver