- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Nonclassical properties of two-mode squeezing-enhanced vacuum state
摘要： We present a new kind of two-mode squeezed vacuum state with two squeezing parameters. Different from the normal univariate two-mode squeezed vacuum state, this new state shows stronger squeezing effect, anti-bunching and entanglement. It is shown that the new squeezing parameter plays an important role in this state.
关键词： fidelity,entanglement,cross-correlation function,squeezing,antibunching effect
更新于2025-09-23 15:23:52
-
Single Photon Emission from a Plasmonic Light Source Driven by a Local Field-Induced Coulomb Blockade
摘要： A hallmark of quantum control is the ability to manipulate quantum emission at the nanoscale. Through scanning tunneling microscopy induced luminescence (STML) we are able to generate plasmonic light originating from inelastic tunneling processes that occur in the vacuum between a tip and a few-nanometer thick molecular film of C60 deposited on Ag(111). Single photon emission, not of molecular excitonic origin, occurs with a 1/e recovery time of a tenth of a nanosecond or less, as shown through Hanbury Brown and Twiss photon intensity interferometry. Tight-binding calculations of the electronic structure for the combined Ag-C60-tip system results in good agreement with experiment. The tunneling happens through electric field induced split-off states below the C60 LUMO band, which leads to a Coulomb blockade effect and single photon emission. The use of split-off states is shown to be a general technique that has special relevance for narrowband materials with a large bandgap.
关键词： STM induced luminescence,antibunching,Coulomb blockade,plasmon,split-off states
更新于2025-09-23 15:19:57
-
Improving photon antibunching with two dipole-coupled atoms in whispering-gallery-mode microresonators
摘要： In the two-atom or multiatom system, the atoms can interact with each other through exchange of virtual photon. This kind of energy exchange is often referred as the dipole-dipole interaction (DDI). Here we consider this DDI system consisting of a pair of two-level atoms strongly coupled with a bimodal whispering-gallery-mode (WGM) microresonator which is driven by an external laser field. Our aim is to explore the photon correlation characteristics of the proposed architecture using realistic experimental parameter values. We compare in detail the quality of photon antibunching (i.e., the smallness of the second-order correlation function) from three involved configurations in cavity quantum electrodynamics (QED): (i) only one two-level atom, (ii) two far apart two-level atoms without DDI, and (iii) two DDI (dipole-coupled) two-level atoms are respectively coupled to the driven WGM microresonator through the evanescent field. We clearly show that the DDI between both atoms can distinctly enhance the photon antibunching even in the weak-coupling regime in configuration (iii) with feature-rich line shapes. We also find that the photon antibunching can be modulated by properly adjusting the atom-cavity coupling strength. In addition, we display that this strong photon antibunching is robust against the cooperative atomic decay. Our DDI-based cavity QED scheme may provide an alternative way to the construction of integrated on-chip single-photon sources.
关键词： photon antibunching,whispering-gallery-mode microresonators,single-photon sources,dipole-dipole interaction,cavity quantum electrodynamics
更新于2025-09-19 17:13:59
-
Generation of single entangled photon-phonon pairs via an atom-photon-phonon interaction
摘要： Antibunching and entanglement play important roles in quantum information processing as antibunching is an essential ingredient for the production of single photons (phonons) and entanglement is a crucial resource for quantum communication and metrology. In this paper, we propose a atom-photon-phonon (tripartite) interaction in a hybrid cavity-atom-mechanics system, and show that both photon and phonon antibunching can be observed simultaneously under the resonant atomic driving. More importantly, the generated single photons and phonons are strongly correlated and entangled with each other, i.e., single entangled photon-phonon pairs are generated via the atom-photon-phonon interaction. The generation of single entangled photon-phonon pairs is the first step to implement entanglement-based quantum state transfer, which is essential for connecting mechanical and optical systems to build hybrid quantum networks.
关键词： antibunching,entanglement,atom-photon-phonon interaction,quantum information processing,hybrid cavity-atom-mechanics system
更新于2025-09-12 10:27:22
-
Nanowire Quantum Dot Surface Engineering for High Temperature Single Photon Emission
摘要： Generating single photons at high temperature remains a major challenge, particularly for group III-As and III-P materials widely used in optical communication. Here, we report a high temperature single photon emitter based on a “surface-free” GaAs quantum dot in a GaAsP nanowire. By using self-catalyzed vapor-liquid-solid growth and simple surface engineering, we can significantly enhance the optical signal from the QDs with a highly polarized photoluminescence at 750 nm. The “surface-free” nanowire quantum dots show photon antibunching up to 160 K and well resolved exciton lines as high as 220 K.
关键词： surface engineering,photon antibunching,quantum dot,single photon source,nanowire
更新于2025-09-12 10:27:22
-
Single-Photon Emission Mediated by Single-Electron Tunneling in Plasmonic Nanojunctions
摘要： Recent scanning tunneling microscopy (STM) experiments reported single-molecule fluorescence induced by tunneling currents in the nanoplasmonic cavity formed by the STM tip and the substrate. The electric field of the cavity mode couples with the current-induced charge fluctuations of the molecule, allowing the excitation of photons. We investigate theoretically this system for the experimentally relevant limit of large damping rate κ for the cavity mode and arbitrary coupling strength to a single-electronic level. We find that for bias voltages close to the first inelastic threshold of photon emission, the emitted light displays antibunching behavior with vanishing second-order photon correlation function. At the same time, the current and the intensity of emitted light display Franck-Condon steps at multiples of the cavity frequency ωc with a width controlled by κ rather than the temperature T. For large bias voltages, we predict strong photon bunching of the order of κ=Γ where Γ is the electronic tunneling rate. Our theory thus predicts that strong coupling to a single level allows current-driven nonclassical light emission.
关键词： photon bunching,Franck-Condon steps,photon antibunching,single-photon emission,plasmonic nanojunctions,STM
更新于2025-09-12 10:27:22
-
Bunching and antibunching in four wave mixing NV center in diamond
摘要： The determination of classical and quantum states through photon bunching and anti-bunching like phenomena may have potential applications in quantum information processing and long-distance quantum communications. We report the photon bunching and multi anti-bunching like phenomena by generating multi-order ?uorescence and four-wave mixing (FWM) at room temperature using the Nitrogen-vacancy (NV) center in diamond. We have implied FWM process to demonstrate the interference pattern emerging from NV of nano-crystals in classical, nonclassical and intermediate (classical and nonclassical) regimes. Intersystem crossing is controlled by the ?uence of incident beams. The interference pattern from dominant ionization of NV- to NVo and NVo to NV- suggests the bunching and anti-bunching like phenomena of photons, respectively.
关键词： antibunching,quantum information processing,quantum communications,diamond,four-wave mixing,photon bunching,NV center
更新于2025-09-10 09:29:36
-
Dynamics of Kerr-like medium with two-mode intensity-dependent cavity fields
摘要： The dynamics of an effective two-level atom coupled to two-mode intensity-dependent quantized cavity fields via a ladder process in the presence of a Kerr medium has been investigated. Eigenfunctions and eigenvalues of the Hamiltonian of the interacting system have been obtained using a unitary transformation method. The cavity field statistics and non-classical properties are investigated numerically through second-order correlation functions. The effect of detuning and the Kerr medium on the non-classical features of the atom-field state has been analyzed. We find that the presence of Kerr non-linearity enhances the non-classical correlation between the correlated beams at short time intervals and increases antibunching at short time intervals.
关键词： intensity-dependent coupling,antibunching,photon statistics,Kerr non-linearity,two-mode ladder model,Cauchy–Schwartz inequality,second-order correlation functions
更新于2025-09-09 09:28:46
-
Higher-order intermodal antibunching for couple-cavity optomechanical system
摘要： Higher-order intermodal antibunching for couple-cavity optomechanical system is investigated by solving Heisenberg’s equations of motion analytically for various field modes using short-time dynamics under strong coupling regime neglecting the effect of dissipation and environmental effects. Temporal variation of this nonclassical effect is also studied for different values of coupling strength and photon-hopping interaction term. The degree of nonclassicality increases as order grows.
关键词： Higher-order nonclassicality,Antibunching,Optomechanics
更新于2025-09-09 09:28:46
-
Super-resolution enhancement by quantum image scanning microscopy
摘要： The principles of quantum optics have yielded a plethora of ideas to surpass the classical limitations of sensitivity and resolution in optical microscopy. While some ideas have been applied in proof-of-principle experiments, imaging a biological sample has remained challenging, mainly due to the inherently weak signal measured and the fragility of quantum states of light. In principle, however, these quantum protocols can add new information without sacrificing the classical information and can therefore enhance the capabilities of existing super-resolution techniques. Image scanning microscopy, a recent addition to the family of super-resolution methods, generates a robust resolution enhancement without reducing the signal level. Here, we introduce quantum image scanning microscopy: combining image scanning microscopy with the measurement of quantum photon correlation allows increasing the resolution of image scanning microscopy up to twofold, four times beyond the diffraction limit. We introduce the Q-ISM principle and obtain super-resolved optical images of a biological sample stained with fluorescent quantum dots using photon antibunching, a quantum effect, as a resolution-enhancing contrast mechanism.
关键词： image scanning microscopy,quantum dots,quantum optics,super-resolution microscopy,photon antibunching
更新于2025-09-09 09:28:46