Employing weak-field homodyne detection for quantum communications
arXiv:2405.14310 · doi:10.1109/JSAC.2025.3543497
Abstract
We investigate the role of weak-field homodyne (WF) measurement for quantum communications over a lossy bosonic channel with coherent state encoding. This kind of receiver employs photon-number resolving (PNR) detectors with finite resolution and low-intensity local oscillator. As a figure of merit, we consider the mutual information for a Gaussian input modulation. We prove an enhancement over Shannon capacity in the photon starved regime, obtained by exploiting information on the mean signal energy to suitably optimize the local oscillator intensity. Thereafter, we investigate the performance of non-Gaussian modulation, by considering a Gamma distribution of the energy of the encoded pulses, and achieve an increase in the information rate with respect to the Gaussian modulation case in the intermediate energy regime, being more accentuated for low values of the PNR resolution.
11 pages, 11 figures
References in corpus (24)
- Classical capacity of the lossy bosonic channel: the exact solution
- Advances in Space Quantum Communications
- Ultimate communication capacity of quantum optical channels by solving the Gaussian minimum-entropy conjecture
- Quantum channels and their entropic characteristics
- Structured optical receivers to attain superadditive capacity and the Holevo limit
- Optical codeword demodulation with error rates below standard quantum limit using a conditional nulling receiver
- The modern tools of quantum mechanics (A tutorial on quantum states, measurements, and operations)
- Quantum Limits in Optical Communications
- Optimized communication strategies with binary coherent states over phase noise channels
- Observing optical coherence across Fock layers with weak-field homodyne detectors
- Capacity of optical communication in loss and noise with general Gaussian receivers
- Tuning between photon-number and quadrature measurements with weak-field homodyne detection
- Hybrid quantum key distribution using coherent states and photon-number-resolving detectors
- Homodyne tomography with homodyne-like detection
- Hybrid near-optimum binary receiver with realistic photon-number-resolving detectors
- Optimization of intensity-modulation/direct-detection optical key distribution under passive eavesdropping
- Optimizing state-discrimination receivers for continuous-variable quantum key distribution over a wiretap channel
- On Approaching the Ultimate Limits of Photon-Efficient and Bandwidth-Efficient Optical Communication
- Approaching the ultimate capacity limit in deep-space optical communication
- Photon information efficiency limits in deep-space optical communications
- Structured Optical Receivers for Efficient Deep-Space Communication
- Beating the standard quantum limit for binary phase-shift-keying discrimination with a realistic hybrid feed-forward receiver
- Quantum Pulse Gate Attack on IM/DD Optical Key Distribution Exploiting Symbol Shape Distortion
- Capacity of a lossy photon channel with direct detection