Related Experiment Video
Updated: Aug 6, 2026
06:42
Generation and Coherent Control of Pulsed Quantum Frequency Combs
Published on: June 8, 2018
Hyperloss from coherent spatial-mode mixing in quantum-correlated networks
Stephan Grebien1, Julian Gurs1, Roman Schnabel1
1Institut für Quantenphysik and Zentrum für Optische Quantentechnologien, Universität Hamburg, Hamburg, Germany.
Nature Communications
|July 25, 2026
Summary
Spatial-mode mismatch in quantum networks causes "hyperloss," degrading squeezed light. Tuning spatial-mode phases can recover lost quantum correlations, a key design consideration for quantum technologies.
Area of Science:
- Quantum optics
- Quantum information science
Background:
- Quantum-correlated networks are essential for quantum technologies like computing and communication.
- Loss-induced decoherence, particularly in squeezed light, hinders quantum advantage.
- Spatial-mode mismatch is often assumed to cause incoherent loss.
Purpose of the Study:
- To investigate the effect of coherent spatial-mode mixing on squeezed light in quantum networks.
- To experimentally demonstrate and quantify the phenomenon of 'hyperloss'.
Main Methods:
- Experimental setup of a minimal two-node quantum network.
- Characterization of squeezing in the presence of spatial-mode mismatch.
- Analysis of correlation recovery by tuning differential spatial-mode phases.
Main Results:
- A minimal two-node network exhibited hyperloss, where 8% mode mismatch converted 5.8 dB of squeezing into a thermal state.
- Hyperloss represents a coherent effect, not merely incoherent loss.
- Lost quantum correlations were recoverable through phase tuning.
Conclusions:
- Spatial-mode mismatch can lead to hyperloss, a significant practical constraint in quantum network design.
- Understanding and controlling hyperloss is crucial for realizing strong quantum advantage.
- Phase tuning offers a method to mitigate hyperloss and recover quantum correlations.
Related Concept Videos
01:182D NMR: Overview of Heteronuclear Correlation Techniques
Heteronuclear correlation spectroscopy is an analytical technique that investigates the coupling between different types of nuclei, often a proton and an X-nucleus, such as carbon-13 or nitrogen-15. This method is commonly used in nuclear magnetic resonance (NMR) spectroscopy to gain insights into complex chemical compounds' structural and compositional aspects. A typical heteronuclear correlation spectrum displays X-nucleus chemical shifts on one axis and a proton spectrum on the other axis.
01:27¹H NMR: Long-Range Coupling
The coupling interactions of nuclei across four or more bonds are usually weak, with J values less than 1 Hz. While these are usually not observed in spectra, the presence of multiple bonds along the coupling pathway can result in observable long-range coupling.
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene π orbitals.
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene π orbitals.
03:35Hybridization of Atomic Orbitals II
sp3d and sp3d 2 Hybridization
01:15Insensitive Nuclei Enhanced by Polarization Transfer (INEPT)
Insensitive Nuclei Enhanced by Polarization Transfer (INEPT) is an advanced Nuclear Magnetic Resonance (NMR) technique specifically designed to detect and enhance the signals of low-abundance nuclei, such as carbon-13 and nitrogen-15, in small molecules. The fundamental principle behind INEPT is the transfer of polarization from a more abundant and highly polarizable nucleus, typically hydrogen-1, to the low-abundance nucleus of interest. This process effectively boosts the NMR signal of the...
01:29Potential Due to a Polarized Object
A neutral atom consists of a positively charged nucleus surrounded by a negatively charged electron cloud. When placed in an external electric field, the external electric force pulls the electrons and nucleus apart, opposite to the intrinsic attraction between the nucleus and the electrons. The opposing forces balance each other with a slight shift between the center of masses of the nucleus and the electron cloud, resulting in a polarized atom. On the other hand, a few molecules, like water,...
03:24Hybridization of Atomic Orbitals I
The mathematical expression known as the wave function, ψ, contains information about each orbital and the wavelike properties of electrons in an isolated atom. When atoms are bound together in a molecule, the wave functions combine to produce new mathematical descriptions that have different shapes. This process of combining the wave functions for atomic orbitals is called hybridization and is mathematically accomplished by the linear combination of atomic orbitals. The new orbitals that...