Category: 4. Physics
-
Quantum frequency conversion and single-photon detection with lithium niobate nanophotonic chips
Chip design and fabrication In this part, the QFC chip is designed and fabricated to realize frequency upconversion between the 1550 nm band (signal) and the 860 nm band (sum-frequency) with a single-frequency pump laser fixed at 1950 nm as shown in Fig. 1a. The device is fabricated on a Z-cut lithium niobate thin film bonded to a…
-
On-chip generation of Bessel–Gaussian beam via concentrically distributed grating arrays for long-range sensing
According to our previous work25, the electric field of the Bessel beam can be obtained from the superposition of multiple diversely polarized wavelets with the same initial phase. Based on the Cobweb structure discussed in ref. 25, the electric field of the generated Bessel beam can be expressed respectively by $$\vec E_B\left( {\rho ,\phi ,z}…
-
A new stochastic diffusion model for influence maximization in social networks
In this section, we describe the proposed diffusion model, in which a stochastic graph models the spread of influence in OSN. We assume that the probability of influence between two users is an unknown random variable, and our proposed model must compute an estimate for this probability. To this end, we propose an algorithm for…
-
Certification of non-classicality in all links of a photonic star network without assuming quantum mechanics
Full nonlocality test for the star network Consider the three-branch star network in Fig. 1. The central node party, B, performs a fixed measurement and outputs a result b. The three-branch parties, A(1), A(2) and A(3), take inputs x1, x2 and x3, respectively, and return respective outputs a1, a2, and a3. The network has three sources, each…
-
Salty polygons | Nature Physics
Share this article Anyone you share the following link with will be able to read this content: Get shareable link Sorry, a shareable link is not currently available for this article. Provided by the Springer Nature SharedIt content-sharing initiative Continue Reading News Source: www.nature.com
-
Quantization observed for ‘heavy’ electrons
RESEARCH BRIEFINGS 14 April 2023 Quantum materials can host exotic phases of matter in which electrons form unusual collective states. Scientists have struggled to observe the quantization that these electronic states are expected to show, but this phenomenon has now been detected in heavy states at the surface of a superconducting quantum material. Continue Reading…
-
Charge transfer driving interfacial reconstructions in perovskite oxide heterostructures
Hereafter, the SIO/NNO and SIO/LNO superlattices are labeled as [SIO2/NNOk]l and [SIO2/LNOk]l, with k the thickness of NNO and LNO in unit cells (u.c.), l the number of superlattice periods, respectively. Unless otherwise stated, all the superlattices were kept at 24 u.c. in thickness, i.e., (2 + k)·l = 24. Structural characterization Reflective high energy electron diffraction (RHEED) oscillations recorded…
-
A Quantum Leap Through Time: Famous Double-Slit Experiment Reimagined
A team of international physicists led by Imperial College London has successfully recreated the double-slit experiment, demonstrating light’s dual nature as both a particle and a wave, but this time in the domain of time rather than space. The experiment relied on materials that change their optical properties in femtoseconds (quadrillionths of a second), which…
-
Physicists lead experiments to explore the force that binds the universe
Credit: Brookhaven National Laboratory The universe began about 14 billion years ago with a single point that contained a vast array of fundamental particles, according to the prevailing theory known as the Big Bang. Under the pressure of extreme heat and energy, the point inflated and then expanded to become the universe as we know…
-
Rethinking the incandescent lightbulb
PRILD system design. (A) Device assembly of the PRILD. (B) Schematic of key components of the PRILD, including an omnidirectional reflective ceramic corundum cavity (CCC), a Janus thermal emitter (JTE) consisting a hBN white emitter and a CNT black emitter, and a visible-transparent infrared-reflective filter (VTIRF) window. (C) Experimentally measured reflectance of the CCC. (D)…