Sources of entanglement are an enabling resource in quantum technology, and pushing the limits generation rate quality is a necessary pre-requisite towards practical applications. Here, we present ultra-bright source polarization-entangled photon pairs based on time-reversed Hong-Ou-Mandel interference. By superimposing four pair-creation possibilities polarization beam splitter, identical photons separated into two spatial modes without usual requirement for wavelength distinguishability or...

High-dimensional quantum entanglement is currently one of the most prolific fields in information processing due to its high capacity and error resilience. A versatile method for harnessing high-dimensional has long been hailed as an absolute necessity exploration science technologies. Here we exploit Hong-Ou-Mandel interference manipulate discrete frequency arbitrary-dimensional Hilbert space. The generation characterization two-, four- six-dimensional entangled qudits are theoretically...

Absorption spectroscopy has long been hailed as an absolute necessity for detecting the properties of complex chemical and biological samples. While conventional using classical light is severely limited by shot noise lacks robustness against experimental imperfections, quantum offers avenue to perform absorption with provable advantages in technical operations measurement precision. Here, we present approach implement entanglement-based assistance Hong-Ou-Mandel interference. Since temporal...

Entanglement and quantum interference are key ingredients in a variety of information processing tasks. Harnessing the generation characterization entanglement high-dimensional state spaces is necessary prerequisite towards practical protocols. Here, we use on beam splitter to engineer hyperentanglement polarization discrete frequency degrees freedom (DOF). We show how independent measurements DOF allow for verification combined space. These results may indicate new paths exploitation stored...

Abstract Deterministic secure quantum communication (DSQC) can transmit secret messages between two parties without first generating a shared key. Compared with key distribution (QKD), DSQC avoids the waste of qubits arising from basis reconciliation and thus reaches higher efficiency. In this paper, based on data block transmission order rearrangement technologies, we propose protocol. It utilizes set single d -level systems as message carriers, which are used to directly encode in one...

Hong-Ou-Mandel (HOM) interferometry is a powerful quantum metrology technique to reconstruct the surface-depth profile of transparent samples with complementary benefits measurement precision and experimental robustness. It generally assumed that trade-off exists between standard HOM sensitivity its ambiguity-free dynamic range. Here we challenge this ``well-known'' assumption through implementation spectrally resolved discrete color entanglement, show well-separated frequencies embedded in...

Quantum interferences of entangled photons have engendered tremendous intriguing phenomena that lack any counterpart in classical physics. Hitherto, owing to the salient properties quantum optics, interference has been widely studied and provides useful tools ultimately broaden path towards ultra-sensitive metrology, ranging from sub-shot-noise sensing high-resolution optical spectroscopy. In particular, interferometric metrology is an essential requisite for extracting information about...

Hong-Ou-Mandel interference is an intrinsic quantum phenomenon that goes beyond the possibilities of classical physics, and enables numerous applications in information science. While photon-photon interaction fundamentally limited to bosonic nature photons restricted phase responses from commonly used unitary optical elements, we present a nonunitary material provides alternative degree freedom control two-photon interference, even revealing anomalous paths do not exist configuration. An...

Abstract Hong-Ou-Mandel interference, the fact that identical photons arrive simultaneously on different input ports of a beam splitter bunch into common output port, can be used to measure optical delays between paths. It is generally assumed great precision in measurement requires contain many frequencies, i.e., large bandwidth. Here we challenge this “well-known” assumption and show use two well-separated frequencies embedded quantum entangled state (discrete color entanglement) suffices...

Counterfactual quantum communication allows distant users to share a message without any physical particles traveling through the channel. Here, we present counterfactual scheme realize multiparty entanglement distribution. We first bipartite distribution create photon–electron by using interaction-free measurements and dots. Then atom–cavity systems are used many photon–photon pairs, which can connect pairs with help of an beam splitter. Consequently, electron spins in optical microcavities...

We propose two counterfactual schemes for tripartite entanglement distribution without any physical particles travelling through the quantum channel. One scheme arranges three participators to connect with absorption object by using switch. Using "chained" Zeno effect, can accomplish task of unique interference probability. Another uses Michelson-type interferometer swap pairs such that photons are entangled. Moreover, distance is doubled as distant objects used. also discuss implementation...

Quantum key distribution (QKD) promises unconditionally secure communications, however, the low bit rate of QKD cannot meet requirements high-speed applications. Despite many solutions that have been proposed in recent years, they are neither efficient to generate secret keys nor compatible with other systems. This paper, based on chaotic cryptography and middleware technology, proposes an universal protocol can be directly deployed top any existing system without modifying underlying...

Structured photons are a crucial resource in both classical and quantum technologies, particularly spin–orbit hybrid photons, enabling various practical applications ranging from ultra-sensitive metrology techniques to quantum-enhanced information processing tasks. However, the two-photon interference of which combines polarization modes complex transverse spatial structures across beam profile, remains unexplored. Here, we present an experimental observation Hong–Ou–Mandel (HOM) photons....

Abstract Two-photon excitation spectroscopy is a nonlinear technique that has gained rapidly in interest and significance for studying the complex energy-level structure transition probabilities of materials. While conventional based on tunable classical light been long established, quantum provides an alternative way towards with potential advantages temporal spectral resolution, as well reduced photon fluxes. By using Fourier transform connects sum-frequency intensity N00N-state...

The Bell basis, a set of maximally entangled biphoton states, is critical prerequisite towards quantum information processing, and many applications have highlighted the requirement for manipulation high-dimensional basis. While states can be created by using ingenious single-photon gates, their implementation complexity in higher dimensions significantly increased. Here we present an elaborate approach to show that adaptive pump modulation enables efficient preparation basis...

The Wiener-Khinchin theorem, the fact that autocorrelation function of a time process has spectral decomposition given by its power-spectrum intensity, can be used in many disciplines. However, applications based on quantum counterpart theorem provides translation between time-energy degrees freedom biphoton wave still remains relatively unexplored. Here, we use (QWKT) to state two-photon joint intensity and cross-correlation temporal signal connected making Fourier transform. mathematically...

The orbital angular momentum (OAM) carried by twisted photons provides a promising playground for high-dimensional quantum information processing. While Bell-state measurement is the cornerstone various applications, deterministic discrimination of complete Bell states with linear optics remains relatively unexplored in OAM state space. Here, we demonstrate theoretical scheme four-dimensional using single-photon hyperentangled analyzer, which auxiliary two-dimensional polarization...

Quantum router is an essential element in the quantum network. Here, we present a fully based on interaction free measurement and dots. The signal photonic qubit can be routed to different output ports according one control electronic qubit. Besides, our scheme interferometric method capable of routing single photons carrying either spin angular momentum (SAM) or orbital (OAM), simultaneously SAM OAM. Then describe cascaded multi-level construct one-to-many router. Subsequently analyze...

Abstract Wave–particle duality is a counterintuitive nature of quantum physics that challenges many common-sense assumptions, and Young’s double-slit interference prototypical example. While most erasure experiments emphasized the choice erasing or marking which-path information one system, we use frequency entanglement to report nonlocal temporal interferometer such which-time determines wave-like particle-like behaviors. Since frequency-entangled photons are created simultaneously by using...

Abstract High‐dimensional frequency entanglement is an enabling resource in quantum technology due to its high information capacity and error resilience. A concise yet efficient method for precisely quantifying dimensionality remains open challenge, owing the difficulties performing required superposition measurements energy‐time domains, complexity associated with full state tomography that scales unfavorably dimensions. With assistance of Hong–Ou–Mandel experiment performs a Fourier...

While the uncertainty principle for linear position and momentum, more recently angular is well established, its radial equivalent has so far eluded researchers. Here we exploit logarithmic position, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m1"> <mml:mrow> <mml:mi>ln</mml:mi> <mml:mtext> </mml:mtext> <mml:mi>r</mml:mi> </mml:mrow> </mml:math> , hyperbolic id="m2"> <mml:msub> <mml:mi>P</mml:mi> <mml:mi>H</mml:mi> </mml:msub> to formulate a rigorous degree...