Limits for realizing single photons
arXiv:2109.06472 · doi:10.1103/PhysRevA.108.063708
Abstract
Exact single photons cannot be generated on demand due to their infinite tails. To quantify how close realizable optical states can be to some target single photon in one dimension, we argue that there are two natural but incompatible ways to specify the target state. Either it can be expressed as a photon with a chosen positive-frequency spectrum, or it can be described as an (unphysical) photon in a chosen positive-time pulse. The results show that for sufficiently short target pulses, the closest realizable states contain substantial multiphoton components. Upper and lower bounds for the maximum fidelity are derived and are expressed as functions of the size of the target state's tail, for negative time or negative frequency, respectively. We also generalize the bounds to arbitrary photon-number states.
References in corpus (20)
- Towards optimal single-photon sources from polarized microcavities
- The Unruh effect in quantum information beyond the single-mode approximation
- Causal and localizable quantum operations
- There are No Causality Problems for Fermi's Two Atom System
- Causality issues of particle detector models in QFT and Quantum Optics
- Impossible measurements require impossible apparatus
- Measurability of Wilson loop operators
- Relativistic causality in particle detector models: Faster-than-light signalling and "Impossible measurements"
- Quantum Information Processing and Relativistic Quantum Fields
- Impossible measurements revisited
- On the Localization of One-Photon States
- Photon localization barrier can be overcome
- Causal State Updates in Real Scalar Quantum Field Theory
- Probabilities and signalling in quantum field theory
- Spacetime diamonds
- Generating multi-partite entanglement from the quantum vacuum with a finite-lifetime mirror
- Shaping single photons and biphotons by inherent losses
- Approaching single-photon pulses
- Strictly localized three-dimensional states close to single photons
- Tunneling times of single photons