Temporal distinguishability in Hong-Ou-Mandel interference for harnessing high-dimensional frequency entanglement

Abstract

High-dimensional quantum entanglement is currently one of the most prolific fields in quantum information processing due to its high information capacity and error resilience. A versatile method for harnessing high-dimensional entanglement has long been hailed as an absolute necessity in the exploration of quantum science and technologies. Here we exploit Hong-Ou-Mandel interference to manipulate discrete frequency entanglement in arbitrary-dimensional Hilbert space. The generation and characterization of two-, four- and six-dimensional frequency entangled qudits are theoretically and experimentally investigated, allowing for the estimation of entanglement dimensionality in the whole state space. Additionally, our strategy can be generalized to engineer higher-dimensional entanglement in other photonic degrees of freedom. Our results may provide a more comprehensive understanding of frequency shaping and interference phenomena, and pave the way to more complex high-dimensional quantum information processing protocols.

Quantum Wiener-Khinchin theorem for spectral-domain optical coherence tomography

“…The synchronous time signal that corresponds to signal photon is also exhibited in the time signal of idler photon such that two-photon relative time delay can be demonstrated in a time process. We note that the synchronous time signal is necessary such that the two-photon relative temporal signal agrees well with the experimental results [17,18]. As shown in Fig.…”

“…In conclusion, we believe that fully harnessing QWKT and its experimental demonstration in frequency-entangled twophoton HOM interference will provide additional tools, e.g., quantum interferometric spectroscopy, ultimately broadening the path towards practical quantum information processing and quantum metrology. For example, with respect to quantum information processing, temporal distinguishability in HOM interference can be harnessed to prepare and characterize high-dimensional frequency entanglement [17,35,36]. With respect to quantum metrology, entanglement-assisted absorption spectroscopy based on quantum interference has been used to detect the absorptive properties of materials and molecules, which has the potential to provide quantum advantages in robustness against noise and loss [11,22,37].…”

High Speed Imaging of Spectral-Temporal Correlations in Hong-Ou-Mandel Interference

“…It has become synonymous with HOM interference, but in reality this dip is only a single-mode representation of a far more complex multi-mode effect. Recent demonstrations of the HOM effect in spatial-temporal [11], and spectral-temporal [12][13][14][15] modes have revealed the complex multi-dimensional nature of HOM interference.…”

Quantum interferometric metrology with entangled photons

“…In particular, the required number of measurements for the task of full quantum state tomography of high-dimensional entanglement in a large state space would increase exponentially versus the dimensions, which is one of the fundamental but important problems concerning entanglement. We use spatial beating of HOM interference with polarization-frequency hyperentangled photons to discretize continuous and broadband spectra into a series of narrow frequency bins [94]. Since the incident entangled photons is in the form of polarization-frequency hyperentanglement, the HOM interference transforms the state into…”